JPS61250892A - Magnetic bubble memory - Google Patents

Abstract

PURPOSE:To obtain a rotating magnetic field with high uniformity and small VI product and to attain low power consumption by providing a solenoid coil applying a DC magnetic field in parallel with the surface of a magnetic bubble memory element in the vicinity of a good conductor case. CONSTITUTION:A coil assembly 4 is inserted into a case RFS assembly in which a board assembly BND and a magnetic current PFC are contained, the case is pressed vertically to arrange a solenoid coil SOC and upper and lower magnets BIMa and BIMb are arranged by bonding on the upper and lower faces. In applying a DC current to the SOC synchronously with a rotating mag netic field generating current, the rotating magnetic field and a DC magnetic field are applied superimposingly on the surface of a chip CHI. Since the DC magnetic field is confined in the RFS and generated as a reverse magnetic field inversed to the holding magnetic field and in parallel with the surface of the chip CHI, when the reverse magnetic field is increased by increasing gradually the DC current, the operating margin of the holding magnetic field in the operating region is measured and the propriety of the holding magnetic field is discriminated easily.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a magnetic bubble memory, and particularly to a magnetic bubble memory suitable for reduction in thickness, size, and power consumption.

[Background of the invention]

Magnetic bubble memory devices, which have been put into practical use in recent years, consist of a rectangular solenoid coil with an asymmetrical structure mounted on a figure-eight ceramic or synthetic resin wiring board on which a magnetic bubble memory chip is mounted. It has a structure in which the X coil and Y coil are inserted and orthogonally arranged. The X coil and Y coil have a structure in which they wrap not only the magnetic bubble memory chip but also a wiring board that is much larger than the chip, so each coil is long from end to end, resulting in large drive voltage and power consumption. turn into. In addition, the X coil and Y coil require a uniform inductor balance in order to provide a uniform and stable in-plane rotating magnetic field to the magnetic bubble memory element, so the coil shapes are different from each other and have an asymmetric structure, resulting in a larger structure. I had no choice but to do so. Furthermore, a pair of permanent magnet plates that apply a perpendicular bias magnetic field to the magnetic bubble memory element and a magnetic shunt plate are arranged on the outer surfaces of these X coils and Y coils, and their peripheral parts are covered with a resin mold. Because of this structure, the stacked layer thickness in the vertical direction increases, which is an obstacle to the demand for thinner magnetic bubble memory devices and 11-inch magnetic bubble memory devices.

The closest prior art to the present invention known to the applicant is Patent Application Publication No. 55129 of 1974. This publication describes the structure of a frame-shaped core that surrounds a chip and a conductive magnetic field reflection box that completely surrounds them. However, no further specific structure is shown, and it is theoretically impossible to make an electrical connection to a chip completely surrounded by a conductor case from outside the conductor case without shorting it. Although it is possible, the description is clearly insufficient for people to think of putting it into practical use, including the fact that the method of attaching permanent magnets, magnetic shunt plates, bias coils, etc. is unknown. In other words, the embodiment of the present invention merely coincidentally coincides with the description in the above-mentioned publication in that a frame-shaped core is used as a result.

[Purpose of the invention]

An object of the present invention is to provide a magnetic bubble memory that can be made thinner.

Another object of the present invention is to provide a magnetic bubble memory that can be miniaturized by reducing the overall volume.

Another object of the present invention is to provide a magnetic bubble memory with reduced power consumption.

Another object of the present invention is to provide a magnetic bubble memory in which the VI product is reduced by reducing the inductance of the rotating magnetic field generating coil.

Another object of the present invention is to provide a magnetic bubble memory that allows or facilitates automation of assembly of component parts.

Another object of the present invention is to provide a magnetic bubble memory capable of increasing the number of connection terminals for input/output, etc., such as increasing capacity.

Another object of the present invention is to provide a magnetic bubble memory in which the inclination angle of the magnetic bubble memory element with respect to the direction of the bias magnetic field can be set easily and with high precision.

Another object of the present invention is to provide a magnetic bubble memory whose cassette can be made smaller.

Another object of the present invention is to provide a magnetic bubble memory whose peripheral circuitry can be manufactured at low cost.

Still another object of the present invention is to provide a magnetic bubble memory that can guarantee starch-stop properties of magnetic bubbles.

[Summary of the invention]

According to one embodiment of the present invention, a drive magnetic circuit using a frame-shaped core is provided. The magnetic bubble memory chip is disposed on a flexible wiring board so as to be surrounded by and substantially flush with the frame-shaped core. The drive magnetic circuit and the magnetic bubble memory chip are housed in a rotating magnetic field confinement case made of a non-magnetic and highly conductive material. A solenoid coil SOC is arranged on the outer surface of the rotating magnetic field confinement case RFS. According to such a configuration, the uniformity of the rotating magnetic field can be improved, the start-stop characteristics can be guaranteed, and the overall shape can be made smaller and thinner.

[Embodiments of the invention]

Next, the present invention will be explained in detail using the drawings.

(Overview of overall structure Figures 1 and 2) Figures 1 and 2 (a) and (b) are diagrams for explaining an embodiment of the magnetic bubble memory device according to the present invention. FIG. 2(a) is a partially broken perspective view, FIG. 2(a) is a bottom view thereof, and FIG. 2(b) is a sectional view taken along line 2B-2B of FIG. 2(a). In these figures, CHI is a magnetic bubble memory chip (hereinafter referred to as a chip). In these figures, the chip CHI is omitted and only one chip is shown, but in this example, two chips are arranged side by side. shall be taken as a thing.

(The chip yield is better with a multi-divided chip configuration that matches the total storage capacity than with one large-capacity chip.) F
The PC is equipped with two chips CHI and a chip C in the four corners.
This is a flexible wiring board (hereinafter referred to as a board) having a wire group extension for connecting the HI and external connection terminals. CoI
is a drive coil (hereinafter referred to as a coil) that surrounds two chips CHI on almost the same plane and is arranged so that opposing sides are parallel to each other, and COR is a rectangular coil assembly CO.
A frame-shaped core (hereinafter referred to as the core) made of a soft magnetic material with a fixing device provided so as to penetrate through the hollow part of the chip CH.
A magnetic circuit PFC that applies an in-plane rotating magnetic field to I is configured. RFS is a rotating magnetic field confinement case (hereinafter referred to as the case) that houses the central rectangular portion of the substrate FPC, two chips CH2, and the entire magnetic circuit PFC.

Case RFS is formed by processing two independent plates,
The upper and lower plates are electrically connected on the side of the case.

A converging portion is formed in the peripheral portion so that the gap in the central portion is narrowed in a slightly wider range than the portion where the chip CHI is arranged. This constriction can also be used to position the magnet. Case PFS uses magnetic field confinement and soft substrate FP
It has the effect of killing two birds with one stone by mechanically supporting C.

In particular, there is a chip C between the case PFS and the chip CHI.
There is a gap SIR on the side surface of the HI, but this gap SIR, including the flat surface of the chip CHI, is coated or filled with silicone resin to prevent foreign matter from adhering to the main surface of the chip during assembly or moisture from entering after assembly. A passivation effect is intended to reduce intrusion into the main surface or side surfaces of the chip. If complete airtight sealing can be achieved on the outside of the case RFS, filling of the resin SIR may be omitted. INM is a pair of inclined plates made of magnetic material placed outside the case RFS, and in Fig. 2, the thickness of the upper inclined plate INM decreases as it moves to the left, and the thickness of the lower inclined plate INM decreases as it moves to the right. It's getting thicker 1. Both have an inclined surface formed on the case RFS side. As the material for the inclined plate INM, soft ferrite, permalloy, or the like, which has a high magnetic permeability μ and a small coercive force Hc, may be used, and in this embodiment, soft ferrite was selected because it is easy to process the inclined surface. MAG is a pair of permanent magnet plates (hereinafter referred to as magnet plates) arranged inside a pair of inclined plates INM and overlapping them.
It is. The ROM is a pair of magnetic shunt plates made of a magnetic material such as soft ferrite and arranged inside each magnet plate MAG and overlapping with it. The magnet plate MAG is formed to have a uniform thickness over the entire surface. The INN is a pair of inclined plates made of a non-magnetic material with good thermal conductivity such as copper, which are placed on the inner facing surfaces of a pair of magnetic shunt plates ROM and overlapped therewith. These inclined plates INN are formed to have substantially the same inclination angle as the inclined plate INM, and have inclined surfaces in opposite directions. Inclined plate INM, magnet plate MAG, magnetic shunt plate HOM
and the inclined plate INN are stacked and arranged so that when they are integrated to form a bias magnetic field generating magnet body BIM (hereinafter referred to as the magnet body), the thickness of the entire laminated plate magnet body is uniform over almost the entire surface. It is formed.

A pair of magnet bodies BIM are adhered to a central flat part surrounded by the constriction part of the case RFS.

BIC is a bias magnetic field generating coil (
(hereinafter referred to as bias coil). The bias coil BIC is driven to adjust the magnetic force of the magnet plate MAG to match the characteristics of the chip CHI, to test for the presence or absence of unnecessary bubble generation defects, and to clear all the bubbles on the chip C) (H). SHI includes a case RFS that houses the board FPC on which the chip CHI is mounted and the magnetic circuit PFC, and a pair of magnet bodies BIMa and B on the outside of the case RFS.
This is an external magnetic shield case (hereinafter referred to as shield case) made of a magnetic material that houses IMb and bias coil BIC. The material for the shield case SHI is He, which has a high magnetic permeability μ and a large saturation magnetic flux density Bs.
A magnetic material with a small value is preferable, and permalloy and ferrite have such properties, but in this example, permalloy, an iron-nickel alloy that is suitable for bending and strong against external mechanical forces, was selected. PKG is a packaging case made of a material such as AΩ, which has high thermal conductivity and is easy to process, and is attached to the outer peripheral surface of the shield case SHI by adhesion or fitting. GNP are contact pads extending from the four corners of the substrate FPC and arranged to contact external connection terminals folded back on the back surface of the shield case SHI. TEF is a terminal fixing plate made of an insulating material that supports and fixes each contact pad GNP at a stepped portion of an opening. REG is sealed in the four inner corners of packaging case PKG, and the shield case RFS assembly is sealed in packaging case PKG.
This is a resin molding agent that is fixed inside G.

(Features of the overall structure, FIGS. 1 and 2) The features of the overall structure of the magnetic bubble memory device shown in FIGS. 1 and 2 are enumerated as follows. However, the features of this embodiment are not limited to these, and other features will become clear from the explanations that follow from Figure 3, but here we will focus on the relationships between each component. The features are described below.

(1) Since the rotating magnetic field generating coil PFC is shaped like a picture frame and the bubble memory chip CHI is arranged on the same plane in the direction of its face, the thickness of the entire bubble device can be reduced. This is because in the current mainstream technology, the upper and lower surfaces of the chip are wrapped around the X and Y coils, so the thickness of the entire device is a function of the sum of the chip thickness, the X coil thickness, and the Y coil thickness.

(2) Since the X coil and Y coil are arranged on almost the same plane, the following effects are achieved compared to the conventional structure in which the Y coil is wound on top of the X coil.

■The total winding length of the coil does not become long. Therefore, the inductance L can be reduced, making it possible to drive at low voltage and reduce power consumption.

(2) The distances between the X coil and Y coil and the chip CHI can be made equal, and the magnetic field distribution can be made balanced.

(3) Since the rotating magnetic field generating coil PFC is surrounded by the conductor case RFS, leakage of magnetic flux is reduced and drive efficiency for the chip CHI can be increased.

(4) The conductor case PFS is a rotating magnetic field Hr generating coil P
It prevents the alternating current magnetic field generated from the FC from leaking to the magnet body BIM with a large magnetic permeability μ, and on the other hand, substantially blocks the passage of the direct current magnetic field of the bias magnetic field Hb that should be applied from the magnet body BIM to the chip CHI. There is an option not to.

(5) Since the conductor case PFS is made of a material such as copper, which is harder than epoxy glass or the like conventionally used for wiring boards, it can mechanically support the chip CHI firmly.

Therefore, when a multiple-chip mounting configuration is used to increase manufacturing yields, variations in the inclination angle between chips have a large effect on magnetic properties, but according to this embodiment, variations in the inclination angle between chips can be reduced. It can be held small.

(6) Flexible film board FPC as a wiring board
By using , the following effects can be obtained.

■The board thickness can be reduced.

■Since the lead bonding method can be used, the thickness occupied by the bonding part can be reduced compared to the conventional wire bonding method.

■The effect of ■ above is due to the magnetic circuit gap (magnetic permeability μ
A bias magnet MAG having a small thickness or a small planar area can be used, which leads to a thinner overall device or a smaller planar area.

■Wiring from the chip CHI can be bent freely. Therefore, the terminal portion can be turned over by 180°, and the planar area of the entire device can be limited.

■The width of the opening for wiring out of the rotating magnetic field confinement case RFS can be made smaller. Therefore, leakage of the rotating magnetic field can be kept to a minimum.

(7) Since the external wiring of the wiring board FPC is concentrated at the corners of the rectangle, the opening of the rotating magnetic field confinement case RFS can be provided at the corner where the influence is least.

(8) Since the function of the inclined plate I'NN is not combined with the magnet or magnetization function, the following effects can be obtained.

■Materials with good workability, such as copper, can be used to form the slope.

■Materials such as copper with good heat sensitivity can be used, and the heat generated by the rotating magnetic field generating coil COI can be efficiently dissipated.

■By using non-magnetic material, magnetic shunt plate HO
It is possible to avoid disturbing the magnetic field passing through M.

(9) It is preferable that the inclined plate INN be as thin as possible in order to reduce the magnetic gap.Compared to the magnet MAG and magnetic shunt plate HOM, the inclined plate INN can be made thinner by limiting its width to the area necessary and sufficient for forming the inclined angle. This makes it easy to form an inclined angle in the thickness.

(10) Since a plate INM made of soft ferrite having a large magnetic permeability μ is inserted between the magnet MAG and the shield case SHI, the magnetic gap therebetween can be filled. The plate INM also contributes to heat radiation. Board I
Since a material having a coercive force Hc smaller than that of the magnet MAG is selected as the NM, the effective thickness of the permanent magnet can be kept uniform.

(11) Since the shield case SHI is made of a magnetic material such as permalloy with a high magnetic permeability μ, the magnetic resistance of the magnetic circuit using the magnet MAG as the magnetic field source can be reduced.
The thickness and planar area of the magnet MAG can be reduced.

(12) Since the shield case SHI is made of a magnetic material such as permalloy with a high saturation magnetic flux density Bs, it has the function of bypassing external magnetic field noise and preventing it from being transmitted to the chip CHI.

(13) The above (11) and (12) each lead to reducing the thickness of the shield case SHI.

(14) Since the shield case SHI uses an iron-nickel alloy such as permalloy, it is suitable for bending and has the function of protecting the parts assembled therein from external mechanical forces.

(15) Rotating magnetic field generating coil PFC and bias coil B
Since both ICs are core-type, the storage efficiency or packaging density within the packaging case SHI or PKG can be increased.

(16) Since the case RFS is inserted between the core COR and the magnetic shunt plate HOM, the interval can be finely adjusted by adjusting the thickness of the rotating magnetic field confinement case RFS and the bending angle in addition to the thickness of the coil COI. . The shorter this distance is, the smaller the overall planar size can be, leading to lower power consumption by reducing the coil length.

However, if the distance is too short, the DC bias magnetic field Hb from the magnet MAG will leak to the core 0OR having high magnetic permeability, and the uniformity of the bias magnetic field around the chip will deteriorate. Therefore, this distance is very critical due to the above-mentioned characteristics, and according to the present structure, it can be precisely adjusted.

(17) Since the constriction portion is provided around the rotating magnetic field confinement case RFS, alignment of the magnet body BIM is easy.

(18) The inclined plate INN is made by arranging two plates made under the same manufacturing conditions so that there is a rotation angle difference of 180° between the top and bottom surfaces of the chip, so that the two plates are made under the same manufacturing conditions. A pair of magnetic shunt plates ROM and a pair of magnets M
AG can be aligned almost parallel.

The features of the overall structure of the magnetic bubble memory shown in Figures 1 and 2 have been explained above, but there are variations of the solenoid coil for measuring the holding magnetic field, which will be described later (Figure 32). , its features will be explained below.

(19) By providing the solenoid coil M○C on the outside of the rotating magnetic field confinement case RFS, the chip C
Since it is possible to generate a DC magnetic field parallel to the plane of the HI, it is possible to measure the holding magnetic field.

(Overview of assembly Fig. 3) Fig. 3 is an assembly perspective view for explaining the procedure for stacking and assembling each component constituting the above-mentioned magnetic bubble memory device, and the same reference numerals as above indicate the same members. . In the same figure, first, a board F has connection parts for input/output wiring protruding from the four corners and an element mounting part in the center.
Board assembly BN with two chips CHI mounted on a PC
D is placed inside an outer case RF Sa in which an insulating sheet 1- is adhered at the position indicated by the dotted line on the bottom surface, and a magnetic circuit PFC is installed on this board FPC. The inner case RFSb is assembled into the outer case RFSa in the upper part thereof, and the side contact portions of the outer case RFSa and the inner case RFSb are electrically connected by soldering or the like. Next, the upper magnet body B I
After arranging M a and the lower magnet body BIMb, the outer edge of the upper magnet body BIM a and the inner case RFSb
A bias coil BIC wound in alignment is placed in a gap (not shown) formed between the inside of the case S and the outside case S.
It is stored in HI a, and the inner case S HI b is installed, and the outer case S HI a and the inner case S HI
Magnetically connect the side contact portion with b by welding or the like. Next, connect the external connection terminal connection portions of the board FPC protruding from the four corners of the inner case 5Hb to the inner case 5H.
On the back surface of Ib, as shown in FIG. 4B, the connectors are folded back and arranged in combination to have a certain shape, and contacts (not shown) are attached to each external connection terminal covered with solder or the like provided at each of these connection parts. A terminal fixing plate TEF with a pad COP mounted in each opening is placed in contact with the terminal fixing plate TEF, and each external connection terminal and contact pad COP are electrically connected by soldering or the like by thermocompression bonding or the like. Next, these assembled bodies are housed in a packaging case PKG, and sealed with a hermetic seal or the like at the contact portion between the terminal fixing plate TEF and the packaging case PKG, and then assembled.

Next, the structure of each component mentioned above will be explained.

(Flexible wiring board Fig. 4) Fig. 4 is a diagram showing a board FPC, where A is a plan view thereof and B is a layout in which the connection parts of external connection terminals protruding from the four corners are folded back and combined. Plan view, C is an enlarged sectional view of 4C-4CC of A, and 4D of A is a plan view.
-4,D is an enlarged sectional view. In the same figure, the board FP
C has a square element protection part 1 in the center, narrow bending parts 2 (2a, 2b, 2c, 2d) at the four corners, and a square external connection terminal connection part (hereinafter referred to as 3 (referred to as connection parts) 3 (3a, 3b, 3c, 3d), and are integrally formed with an almost windmill-like overall shape, and on the opposite side of the element protection part 1. 2 described later
A rectangular opening 4 (4a, 4b) with a double frame structure in which the chip CHI is mounted and the terminals thereof are connected, and three perforations 5 (5a, 5b, '5c) for positioning are provided.
Furthermore, a board protrusion 6 for positioning is provided at the tip of one connecting portion 3c.

In addition, as shown in FIG. C, this FPC board is made by forming a copper thin film on a base film 7 made of a polyimide resin film with a thickness of about 50 μm, for example, via an epoxy adhesive 8, and then applying the copper thin film to the desired shape. By etching into a pattern shape, wiring leads 9a as shown in FIG.
A circular external terminal 9b and an oval coil lead connection terminal 9c.

Patterns such as a symbol 9d and an index mark 9e are formed, and a transparent or semi-transparent cover film 10 is adhered to the upper surface of these through an adhesive 8 made of the same material as described above. . And this board FP
In the opening 4 of C, an opening with highly accurate dimensions is formed in the base film 7 on which the chip CHI (not shown) is mounted, and an opening with relatively large dimensions is formed in the cover film 1o on the upper surface side. Further, a wiring lead 9a is exposed between the base film 7 and the cover film 10, and a tin plating layer 1 is formed on the surface of the wiring lead 9a.
1 is formed, and the opening shape is formed to have a two-layer structure and a double frame structure.

On the other hand, in the connecting portion 3, as shown in the figure, a circular opening 12 is formed at a portion of the cover film 10 corresponding to the circular external terminal 9b and the oval external terminal 9c (not shown). External terminal 9 exposed from
A solder layer 13 is formed by plating or dipping on the copper thin film patterns b and 9c. The external terminals 9b, 9c provided on these connecting portions 3 are the respective connecting portions 3a, 3b, 3c, 3d and the bent portion 2a.

2b, 2c, 2d and each wiring lead 9a formed continuously on the element protection part 1-, and these wiring leads 9a are connected to each opening 4a provided in the element mounting part 1.
, 4b, each connecting portion 3a, 3b, 3c, 3
The tips of the blocks are assembled into each opening 4a,
4b is exposed. That is, as shown in FIG. A, the wiring lead 9a of the connecting part 3a is located at the upper left of the opening 4a, the wiring lead 9a of the connecting part 3b is located at the lower left of the opening 4b, and the wiring lead 9a of the connecting part 3c is located at the lower left of the opening 4b. is located in the upper right corner of the opening 4a, and the wiring lead 9a of the connection part 3d is located in the opening 4b.
are wired at the bottom right of each. In this FPC board, the connecting portions 3a, 3b, 3c, and 3d are formed into bent portions 2a in a subsequent process.

Each external terminal 9b is bent at 2b, 2c, and 2d and assembled as shown in FIG. B, forming a solder layer 1-3.
, 9c are exposed on the surface, and the surfaces of the wiring leads 9a, symbols 9d and index marks 9e are covered with the cover film 10, so that these patterns can be easily read through the cover film 10. It is configured.

In such a configuration, the substrate FPC uses a polyimide resin film, and each bent portion 2 is provided at the four corners of the element protection portion 1.
Each connection 3a, 3b, 3 via a, 2b, 2c, 2d
c, 3d, and each of these connecting parts 3
By folding and combining a, 3b, 3c, and 3d to form the external terminal section, the element protection section 1 and the connection section are separated into two parts.
Since it has a layered wiring structure, the area of the element protection part 1 can be increased without reducing the area of the connection part 3, and at the same time, it is possible to increase the number of external terminals, and the overall shape can be made smaller. .

In addition, in such a configuration, the wiring leads 9a from each external terminal 9b to each opening 4a, 4b of the element protection part 1
Since the time can be significantly shortened, the influence of external noise etc. can be significantly reduced. That is, signals with a high S/N ratio can be input and output. Furthermore, a board protrusion 6 is provided at one end of the connecting part 3c, and an index mark 9e is provided on this protrusion 6, so that when the board is folded back and assembled, it can be used for displaying the central part of the board.
I (see Figure 2) can be used for positioning when assembling, distinguishing the type of wiring lead 9a, or displaying the product model. It can be streamlined. Additionally, holes 5a, 5b, 5c are provided at both ends of the element protection portion 1 of the FPC board.
By providing this, it becomes easy to distinguish between the left and right sides of the FPC board, position the chip CH, etc., and it is also possible to streamline assembly.

(Substrate Assembly Figures 5.6.7) Figure 5 shows a plan view of the chip CHI mounted on the FPC substrate described above. In the same figure, the board FPC
In the element mounting part 1, two chips CHI are placed in the opening 4a,
A board assembly BND is constructed by being mounted in parallel between the chips CHI and IMb, and one of the chips CHI is constructed by integrating two blocks of IMb chips, as shown in the enlarged plan view in FIG. Two chips CHI constitute 4 blocks, a total of 4 Mb chips. In one block of the chip CHI shown in FIG. 6, thick lines indicate conductor patterns and thin lines indicate chevron pattern transfer paths, respectively. In addition, the chip CI (I is the seventh
As shown in enlarged cross-sectional views in FIG.
A gold bump 15 is placed between the wiring lead 9a on which the gold bump 15 is formed.
It is mounted by lead bonding using Au-Sn eutectic using a thermocompression bonding method.

According to such a configuration, the openings 4a, 4 of the substrate FPC
The wiring lead 9a of b and the bonding pad 14 of the chip CHI are connected by lead bonding using Au''Sn eutectic, and the chip CHI can be supported and fixed, so the connection strength can be greatly improved and the thickness can be reduced. In addition, the surface of the chip CH process can be
Since the surface of the chip CHI is covered by the element mounting portion 1, the surface of the chip CHI is protected, the handling property can be improved, and the mechanical strength of the substrate FPC can be maintained. Moreover, according to such a configuration, each chip C
Since the HI consists of two blocks and the two chips CHI consists of four blocks, each connection portion 3a is the closest to each block.

Wiring can be distributed to 3b, 3c, and 3d, and symmetry of chip CHI arrangement can be obtained, making testing, inspection, etc. extremely easy. Furthermore, four connection parts 3a, 3b, 3c,
3d, the wires for the magnetic bubble detector DET and pine pulley of each chip CHI are distinguished from other functional wires and concentrated at one connection point, and this connection point is selected to be away from the noise source. By arranging them as such, input/output signals with extremely low noise can be exchanged.

(Drive Magnetic Circuit FIGS. 8 and 9) FIG. 8 is a diagram showing the magnetic circuit PFC, and FIG. 8A is a perspective view, and FIG. 8B is a plan view showing the drive magnetic circuit. In the figure, the magnetic circuit PFC includes four sets of coils 20a, 20b, 20, which are wound in the direction of the arrows on mutually parallel opposing sides of a frame-shaped core COR made of a soft magnetic material.
A coil COI consisting of c and 20d is wound, and the coils 20a and 20b on opposite sides are connected to a connection point 2]-b
The X coil 22a is wound in series through the coil 20.
c and 20d are wound in series via the connection point 21a to form Y
Each of them constitutes a coil 22b.

Then, currents Ix and Iy (for example, triangular non-current) whose phases are different by 90 degrees are applied to the X coil 22a and the Y coil 22b.
As shown in Figure B, a leakage magnetic field Hx is generated in the X-axis direction and a leakage magnetic field Hy is generated in the y-axis direction.
It is supplied as a rotating magnetic field to the two chips CHI mentioned above.

In addition, the magnetic circuit PFC configured in this manner has windings arranged around a rectangular parallelepiped magnetic core 23 made of one soft magnetic material with taps 24 for each block, as shown in a perspective view in FIG.
are provided and wound in series to form a pair of coils, for example coil 20.
After forming a pair of X coils 22a consisting of coils 20a and 20b, a wide groove 25 having a constant number 11 and a narrower groove 26 are formed by cutting between each coil 20a and 20b. Thereafter, the wide grooves 25 which are cut from the narrow groove 26 and then glued together in directions perpendicular to each other are formed into a picture frame shape as shown in FIG. Alternatively, the pair of X coils 22a may be formed by winding the coils 20a and 20b through the taps 24 around the rectangular parallelepiped core 23 in which the wide groove 25 and the narrow groove 26 described above are formed in advance. . Furthermore, the pair of Y coils 22b described above are formed in exactly the same manner.

In such a configuration, the coils 20a and 20b are wound in series around the rectangular parallelepiped magnetic core 23 with taps 24 provided, so when assembled as shown in FIG. 8, the wires are connected by crossing each other ( connection points), and the winding routing can be simplified.

According to such a configuration, the X coil 22a and the Y coil 2
2b has a symmetrical structure, resulting in a rough coupling,
The inductance balance is improved, and magnetic interference between magnetic bodies due to leakage magnetic fields can be prevented. Further, since the magnetic circuit PFC has a frame-shaped structure that is not placed on the upper or lower surface of the chip CHI, the thickness in the stacking direction is reduced, making it possible to reduce the thickness.

(Rotating magnetic field confinement case Fig. 10.11.12) 1st
Figure 0 is a diagram showing the case RFS, and Figure A is a plan view.
Figure B is a sectional view taken along the line 10B-10B. In the figure, the inner case RFSb has a frame-shaped constriction part 30 whose central part is concave, and whose opposing end sides extend upward by approximately 90 degrees.
The case RFSb is made of a highly conductive material, for example, an oxygen-free material. It is formed by pressing a copper plate.

In this case, the constricted portion 30 and the bent portion 31 can improve the mechanical strength of the inner case RFSb in the torsion direction, and can appropriately limit the outer diameter dimensions in the longitudinal and lateral directions between the bent portions 31 facing each other. can. The aperture section 30 also includes a magnet BTMb disposed on the outer surface side of the case RFSb and a chip CH disposed on the inner surface side.
The distance between I and I can be adjusted as appropriate. In addition, 4
The cutout portions 32 provided at the corners are each bent portion 2a of the board FPC disposed within this case RFSb.

It forms the drawer parts 2b, 2c, and 2d.

According to such a configuration, the inner case RFSb can be formed by a press working method, so that it can be manufactured with high precision dimensions and at a low cost.

Note that, although oxygen-free copper is used for the inner case RFSb, a plate material made of copper, silver, gold plate, or an alloy plate thereof may be used.

FIG. 11 is a diagram showing an outer case RFSa corresponding to the above-described inner case RFSb, with FIG. 11A being a plan view and FIG. 11B being a sectional view taken along line IIB-11B. In the same figure,
This outer case RF Sa is similar to the inner case R described above.
It is formed using the same material and manufacturing method as FSb, and its structure is almost the same as described above, with a frame-shaped constriction part 33 whose center part is concave, and the opposite end thereof is bent upward at approximately 90 degrees. It is configured to include a bent portion 34 and a notch portion 35 cut diagonally at each of its four corners. In this case, the mutually opposing bent portions 34 are formed so that the inner dimensions thereof are approximately the same as the outer dimensions between the bent portions 31 of the inner case RFSb described above, and the height H is increased. has been done. Note that the constriction portion 33 and the notch portion 35 are connected to the inner case RF described above.
It is formed to have substantially the same dimensions as Sb.

The outer case RF S a and the inner case RFS b configured in this way are shown in a plan view in FIG.
By inserting the inner case RFSb into the outer case RFSa as shown in the 12B-12B cross-sectional view in FIG. , integrated case R
FS is assembled.

(Case assembly Figure 13) Figure 13 shows the board assembly BND inside the case RFS mentioned above.
This figure shows a cross-sectional view of the outer case RF Sa, in which a polyimide film 36 with a thickness of approximately 0° and one roll is adhesively arranged on the bottom surface of the outer case RF Sa as an electrically insulating sheet. The board assembly END is placed on this film 36, and the magnetic circuit F is placed on the periphery of the board assembly END.
The PCs are respectively arranged, and after applying an epoxy adhesive 37 to the upper surface of the board assembly BND, the inner case RFSb is inserted into the upper part of these and arranged to be bonded. In this case, the inner surface of the bent portion 34 of this outer case RFSa and the bent portion 3 of the inner case RFSb
The outer surface of 1 is electrically and mechanically joined by metal flow, soldering, etc. at the portion indicated by the X mark. Also,
A gap between the outer case RFSa and the inner case RFSb is filled with silicone resin SIR, and the board assembly BND and the magnetic circuit PFC are fixedly arranged.

In this case, the bent portions 2 of the board FPC are inserted into each notch portion 32, 35 (not shown) provided at the four corners of the outer case RF Sa and the inner case RFSb.
(2a, 2b, 2c, 2d) are drawn out.

38 is a lead wire for connecting the coil COIs or connecting the coil COI and the external terminal 9c provided on the FPC board.

In such a configuration, when a leakage magnetic field is generated by driving the magnetic circuit FPC, an induced current flows through the case RFS to form a closed loop, and the rotating magnetic field is confined within the case RFS by this induced current. Therefore, a uniform rotating magnetic field is applied to the chip CHI.

According to such a configuration, the chip CHI mounted on the board FPC is held in the concave part of the central part between the outer case RF Sa and the inner case RFSb, and the magnetic circuit PFC is held in the convex part of the peripheral part. Since they are arranged in parallel, the packaging effect can be improved and the ease of assembly can be greatly improved.

In addition, outer case RF S a and inner case RFS
By reducing the volume covered by b, the VI product (volume) can be reduced, and the magnetic circuit PFC that generates the rotating magnetic field can be downsized. Furthermore, by providing concave portions formed by the constricted portions 30 and 33 in the outer case RF Sa and the inner case RFSb and reducing the gap between the opposing concave portions, the rotating magnetic field has a component perpendicular to the plane of the chip CHH ( Z component) is close to zero and there is only a horizontal component,
Uniformity can be improved.

(Magnet Figure 14) Figure 14 is a diagram showing the magnet body BIM, in which Figure A is a plan view, Figure B is a side view, and Figure C is a front view.

In the figure, the magnetic body BIM includes an inclined plate IN made of a non-magnetic material, such as copper, and one of the opposing surfaces has a predetermined inclined surface.
N, this inclined plate ■ A first magnetic shunt plate HOM□ having a uniform plate thickness disposed on the inclined surface side of NH, and this first magnetic shunt plate HOM
, a magnet plate MAG with a uniform thickness placed on the upper surface side and a second magnetic shunt plate HOM2 having an inclined surface on the upper surface side of this magnet plate MAG are sequentially laminated and integrated with an epoxy adhesive. The laminated plate thickness is uniform over almost the entire surface. A uniform magnetic field for generating a bias magnetic field is emitted from the upper and lower surfaces of this magnet body BIM over almost the entire surface.

(Bias Coil FIG. 15) FIG. 15 is a diagram showing the bias coil BIC, where A is a perspective view and FIG. B is a cross-sectional view taken along line 15B-15B. In the same figure, the bias coil BIC has a winding 40 whose outer surface is coated with an insulating member such as a thermosetting resin, and is wound in an array with a cross section of 5 x 4 wires so that the overall shape has a picture frame shape. After that, it is crimped by heat welding, cooled, and formed into a frame shape of a predetermined value. In this case, the thermosetting resin coated on the outer surface of each winding 40 is thermally welded to each other, and each winding 40 is clogged and formed by pressure bonding, and by cooling, each winding 40 is hardened in a bundled state. Therefore, it is formed into a predetermined picture frame shape.

(Mounting the magnet and bias coil on the case assembly
(FIG. 16) FIG. 16 is a sectional view of the case RFS assembly described in FIG. 13 incorporating the magnet body BIM and bias coil BIC. In the same figure,
An upper magnet body B I M a and a lower magnet body BIM b are adhesively arranged on the upper and lower surfaces of the case RFS assembly that houses the board assembly BND and the magnetic circuit PFC inside, respectively.
Further, a bias coil BIC is housed in a frame-shaped groove formed by being surrounded by the peripheral edge of the upper magnet B I Ma and the bent portion 31 of the inner case RF8b. In this case, the upper magnet BIMa and the lower magnet BIMb are made of the same material with 9 dimensions, and these magnets BIMa and BIMb have their inclined plates I
The NN side is disposed in close contact with a concave portion surrounded by the constricted portion 30 of the inner case RFSb and a concave portion surrounded by the constricted portion 33 of the outer case RFSa.

In such a configuration, a pair of magnet bodies BIMa,
Since the BIMb is placed and the bias coil BIG can be placed in the frame-shaped groove formed on the periphery of the BIMb,
The overall thickness of each component in the stacking direction is reduced, making it possible to make it smaller and thinner. In addition, the outer case RF Sa
A frame-shaped space groove is formed between the outer edge portion of the lower magnet body BIMb, and the bias coil BIC is inserted into this portion.
Alternatively, a new bias coil may be provided, and furthermore, a bias coil may be formed by winding a wire as a coil bobbin.

(Magnetic shield cell Figure 17, 18, 19) No. 17
The figures show the shield case SHI, with figure A being a plan view and figure B being a 17B-17B cross-sectional view thereof. In the same figure, the outer shield case S HI a has a flat portion 51 and an end side opposite to the flat portion 51 that extends upward by approximately 90 mm.
The folded part 52 that is folded back at the same time, and the folded part 52
The shield case S HI a has a recess 53 partially cut out in the center thereof, and a notch 54 cut diagonally at each of its four corners.This shield case S HI a has a high magnetic permeability. It is formed by pressing a material having a high saturation magnetic flux density and preferably a high thermal conductivity, such as a permalloy plate.

FIG. 18 is a view showing an inner shield case 5HIbl corresponding to the above-mentioned outer shield case 5HIa, with FIG. 18A being a plan view and FIG. 18B being a 18B-18B sectional view thereof. In the figure, this inner shield case S HI b
is formed using the same material and manufacturing method as the above-mentioned outer shield case S HI a, and its structure is almost the same as above, with a flat part 55 and an opposite edge of the flat part 55 extending upward at approximately 90 degrees. A folded portion 56 and a recessed portion 57 partially cut out in the center of the bent portion 56.
and a notch 58 cut diagonally at each of its four corners.
It is composed of: In this case, the mutually opposing bent portions 56 have an outer dimension approximately equal to the inner dimension between the bent portions 52 of the outer shield case SHIa described above, and have a reduced height H. It is formed by

The outer shield case 5HIa and the inner shield case 5HIb configured in this way are arranged inside the outer shield case SHIa as shown in FIG. 19A as a plan view and as shown in FIG. Insert shield case 5HIb and remove outer shield case S.
Spot welding or solder welding is applied to the recess 59 formed by the recess 53 of the HI a and the recess 57 of the inner shield case 5HIb, and the outer shield case S HI a is assembled by magnetically and mechanically fixing the recess 59. It will be done.

In such a configuration, the outer shield case S HI
a bent portion 52 and inner shield case 5HI
By setting the bent portions 56 of b in the lateral direction, that is, in a direction that intersects with the stacking direction, by aligning them with the stacking direction, the lateral dimension can be reduced, and the structure can be made compact and highly integrated with the component parts. It becomes possible.

(Magnetic shield case assembly FIG. 20) FIG. 20 shows the case RFS assembly, which incorporates the board assembly BND and magnetic circuit FPC inside the shield case SHI assembly described in FIG. Magnet plate B I
Ma, B IMb.

2 is a sectional view showing an assembly including a bias coil BIC. In the same figure, inside the outer shield case S HI a, there is an upper magnet body B I M a from the bottom side to the center, a bias coil BIC at the periphery, and a case RFS assembly (board assembly BN inside).
D, magnetic circuit PFC etc. are incorporated), lower magnet body B After sequentially stacking and arranging the lower magnet body B IMb, the inner shield case 5HIb is inserted, and the above-mentioned outer shield case S
It is fixed and sealed by welding in a recess 59 (see FIG. 19) formed by the recess 53 of HIa and the recess 57 of inner shield case 5HIb. In this case, by filling the shield case SHI with grease or the like, the internal components will come into close contact with each other, and the heat generated from the case RFS will be transferred to the shield case SHI.
It can be released to the outside through. Also, case R
The heat dissipation effect can be improved by making the FS and the shield case SHI contact each other at their sides by press-fitting.

In such a configuration, the outer shield case S I (
Each structure is stacked between the outer shield case S HI a and the inner shield case S HI b by arranging the case RFS assembly on the bottom side of Ia so that the bent parts 31 and 34 thereof face each other. Since the parts can be placed closely together, it is possible to make the device smaller and thinner, and at the same time, a heat dissipation effect can be obtained.

(Packaging case Fig. 21) Fig. 21 is a diagram showing the packaging case PKG, where A is a plan view and B is a 21B-21Bvrt.
It is a figure m. In the same figure, packaging case PK
G is a material with good thermal conductivity, for example, 0.5+nm in thickness
It is formed by drawing an aluminum plate, and has a black coating on its outer surface (not shown). This packaging case PKG can be used in combination with the outer shield case 5HIa by improving its shape.

In such a configuration, this packaging case P
The KG serves as an outer case after the magnetic bubble memory device is completed and also functions as a heat sink, and its inner corner also functions as a mold during resin molding by the potting method described later.

(Terminal fixing plate and contact pad Fig. 22.23)
FIG. 22 is a diagram showing the terminal fixing plate TEF, in which FIG. 22A is a plan view, FIG. 22B is a sectional view taken along line 22B-22B, and FIG. 22C is a rear view thereof. In the same figure, the terminal fixing plate TEF is made of an electrically insulating material, for example, a glass epoxy resin plate 60, and its external shape is such that it can be freely inserted into and removed from the opening of the packaging case PKG. The resin plate 6 is formed to have dimensions in the direction.
A large number of through holes 61 are formed in a matrix arrangement at predetermined intervals in the vertical and horizontal directions except for the peripheral area of 0, and the corners of these through holes have cross sections that are not rotationally symmetrical. A concave non-through hole 62 is provided, and a mark 63 made of, for example, a white coating film for locating directionality or features is attached inside the non-through hole 62. In addition, a large number of through holes 6 are formed in this resin plate 60.
As shown in FIG. 1, large-diameter openings 64 are coaxially communicated with each other on the back side of the plate, and all of these openings 64 have a depth of about 60% of the plate thickness. In addition, it communicates with the through hole 61 with a step in the middle. Also,
As shown in Figure C, the back side of this resin plate 60 has a depth approximately equal to the depth of the opening 64 along its peripheral portion, and has a different width in the plane direction and a concave cross section. A groove 65 is formed, and the above-mentioned coil CO is placed inside this groove 65.
It constitutes the passage section and connection section of the winding of I and the winding of bias coil BIC. In addition, the corner portion 6 of this resin plate 60
6 does not have a concave shape, but has a predetermined plate thickness, and forms a contact surface with the inner surface of the packaging case PKG described above. In this way, the back side of the resin plate 60 is formed to have a two-tiered structure with different plate thicknesses.

FIG. 23 is a diagram showing the contact pad GNP, with FIG. 23A being a plan view and FIG. 23B being a sectional view taken along line 23B-23B. In the same figure, the contact pad GNP is formed by forming a nickel plating layer 7 on the surface of a piece 70 punched out of a highly conductive material, for example, a copper plate with a thickness of approximately 005 mm.
1. It is constructed by forming a gold plating layer 72.

(Final assembly FIG. 20.4.2) For each component configured in this way, first, the shield case assembly described in FIG. 20 is inserted into the packaging case PKG described above. In this state, each connection part 3B, 3b, 3c, 3d (fourth
(see Figure A) are each bent part 2a, 2b, 2c, 2
It bends at about 90 degrees from d and protrudes. Next, resin molding is performed on the four corners of this packaging case PKG by the botting method, and this packaging case P
Each unique part is fixedly arranged within the KG. Subsequently, these connecting portions 3a, 3b, 3c, and 3d are further bent at approximately 90 degrees at the corresponding bending portions 2a, 2b, 2c, and 2d, and attached to the outer surface of the inner shield case 5HIb with adhesive as shown in FIG. After combining as shown in B, contact pads GNP are mounted in each opening 64 on the back side of the terminal fixing plate TEF, or contact pads GNP
The packaging case P is fixed by fixing the sides with adhesive.
KG and each connection part 3a, 3b, 3c'.

Place it in contact with 3d. In this case, each connection part 3a.

Since the arrangement pitch of each external terminal 9b provided in 3b, 3c, and 3d matches the arrangement pitch of each contact pad GNP, each external terminal 9b and contact pad GNP are in electrical contact. Next, by inserting, for example, a heating element with a thin tip into each through hole 61 from the back side of the arranged terminal fixing plate TEF and thermocompression bonding the contact pad GNP, each contact pad CN'P corresponding to each external terminal 9b is attached. are electrically connected and the terminal fixing plate TEF is also mechanically fixed at the same time, completing the magnetic bubble memory device shown in FIG.

(Magnetic Bubble Memory Element No. 24.25.26.27.
Figure 28) Figure 24 shows the above-mentioned magnetic bubble memory chip C.
It shows a cross-sectional view of the vicinity of the bonding pad PAD of HI. In the same figure, GGG is gadoljnju
m-gallium-garnet substrate, T-
PE is a bubble magnetic film formed by liquid phase epitaxial growth, and an example of its composition is shown in Table 1 below.

Table 1 ■ON indicates an ion implantation layer formed on the surface of the LPE film to suppress hard bubbles. The SPI is the first spacer, for example 3000 mm thick SIO, formed by gas phase chemical reaction.

CNDl and CND2 indicate two conductor layers, which have the function of controlling bubble generation, copying (splitting) and exchange, which will be described later, and the lower first conductor layer CNDI is M o
, and the upper second conductor layers CND2 are each formed of a material such as AU. SF3 and SF3 are interlayer insulating films (second and third spacers) made of polyimide resin or the like that electrically insulate the conductor layer CHD and the transfer pattern layer P formed thereon, such as permalloy. PAS is a passivation film made of a SiO2 film or the like formed by a vapor phase chemical reaction method. PAD indicates a bonding pad of the chip CHI, to which a thin connector wire such as an Afl wire is bonded by thermocompression bonding or ultrasonic bonding. This bonding pad PAD is the lower first layer PAD,
is Cr, the second layer PAD2 in the center is Au layer, and the upper third layer P
AD3 is formed of a material such as an Au plating layer, and the second layer PAD2 and third layer PAD3 are formed of Cr, Cu, etc.
It may be made of materials such as. P indicates a layer used for the bubble transfer path, the bubble division 9 generation, replacement and detection section, and the card rail section, and in the following description, it will be expressed as a transfer pattern layer for convenience.

In the example of FIG. 24, this transfer pattern layer P is transferred to the lower layer P1.
Although e-Ni is used for the upper layer P2 and Fe-Ni is used for the upper layer P2, it is also possible to interchange the two materials vertically as described above.

Hereinafter, an example in which the transfer pattern layer consisting of multiple layers described above is applied to each part of the chip CHI will be explained using the plan views from FIG. Note that they are represented by the same contour line because they are the same. Figure 25 shows the bubble detector part, where MEM is the main magnetoresistive element, which uses the change in resistance value when bubbles stretched in a strip shape in the horizontal direction pass through it to detect the presence or absence of bubbles. Detect. MED is a dummy magnetoresistive element having a pattern similar to that of the main magnetoresistive element MEM, and is used to detect noise components due to the influence of a rotating magnetic field. Above the main magnetoresistive element MEM, several ten stages of bubble stretchers ST are formed, although only two stages are shown, which stretch the bubbles laterally and transfer them downward. Note that PR is embossed in the bubble transfer direction.

ER is a bubble eraser, and when a bubble reaches the conductor layer CND, it is erased. There are three rows of patterns around this detector and between the dummy and main detection to expel unnecessary bubbles generated inside the guardrail GR and remove bubbles generated outside the guardrail GR. This prevents unnecessary bubbles from entering inside. In the plane pattern diagrams shown in FIG. 25 and subsequent figures, patterns other than the conductor layer CND indicate the transfer pattern layer P explained in FIG. 24. In the same figure,
By forming the magnetoresistive elements MEM and MED with multilayer magnetic layers, the signal-to-noise ratio (S/N ratio) was improved. For example, when a three-layer permalloy layer with a SiO2 film interposed between each layer is used as a transfer pattern, the S/N ratio can be improved by more than twice compared to a single-layer permalloy layer, as shown in Table 2 below. I can do it.

Table 2 Furthermore, the performance of the guardrail GR is also improved by reducing the holding force He, such as increasing the rate of eliminating unnecessary bubbles.

FIG. 26 shows the magnetic bubble generator GEN, and by making the transfer pattern layer P multilayer, the current generated by the magnetic bubble can be reduced, and the life of the conductor layer CND of the magnetic bubble generator can be extended. It became possible. Therefore, a semiconductor element with a small current capacity value can be used for the drive circuit of the conductor layer CND, and the cost can be reduced.

FIG. 27 shows a minor loop m formed by transfer patterns such as P a ” P h, a write major line WML formed by transfer pattern rows such as Pw□ to Pw3, and a swap loop 1 formed by a hairpin-shaped conductor layer CHD. ~
It shows the part. In FIG. 1, P7 is the same as the transfer pattern P7 in the bubble generator GEH in FIG. 26; in other words, the pull generated by the bubble generator GEN is P.

~ Write major line WM through the transfer path of P7
Transferred to L. When a current is applied to the swap conductor layer CHD, the transfer node (turn Pd(7)) magnetic bubble of the minor loop m is transferred to the transfer pattern PW9 of the major line WML through the transfer patterns PΩ and Pm, and the magnetic bubble is transferred from the major line Pw1 to the transfer pattern PW9 of the major line WML. Magnetic bubble is transfer pattern Pk
+ P jt P i and transferred to the minor loop transfer pattern Pa, where bubbles are exchanged, that is, information is rewritten. Note that the rightmost minor loop md is not provided with a swap gate, but this is a dummy loop in which no magnetic bubble is injected to reduce the peripheral effect. By multilayering the transfer pattern layers Pi-Pm at the exchange position in this way, magnetic bubbles can be exchanged with a small current value.

Further, as shown in FIG. 28, a magnetic bubble copying machine, that is, a divider, can be driven with a small current value as well. In the figure, magnetic bubbles are normally transferred in the order of Pn to Pg and Ps to Px, and when a current is passed through the conductor layer CHD, the bubbles are divided at the position of the transfer pattern Pg, and one divided magnetic bubble is generated. The bubble is transferred to the read major line RML via Py, P8 to P1o.

(Holding magnetic field and rotating magnetic field FIG. 29) Magnet plate MAG is arranged at an angle of about 2 degrees with respect to chip CHI. This is the bias magnetic field Hb for the chip CHI.
The holding magnetic field Hdc is applied with a slight deviation from the vertical direction, thereby improving the start and stop margins of bubble transfer by approximately 6 Oe.
(Figure 29A).

As shown in Figure 29A, the magnet body BIM and the chip CHI
Due to the inclination of the angle θ with , the DC magnetic field Hz has a component Hdc in the xy plane.

Then, the magnitude of this in-plane component Hdc is Hdc・si
nθ, usually HdC-8inO=5[Oe]~6(
The inclination angle θ is selected so that the angle θ is Oe). Also, the direction of this in-plane component Hdc is the starting point and direction of the rotating magnetic field Hr.
It is tilted to match the stop (St/Sp) direction (+x-axis direction). And this xy plane component Hd
c is the start/stop of the rotating magnetic field Hr (St/Sp
) This is a well-known magnetic field that has an effective effect on motion and is called a holding field. Note that the magnitude of the bias magnetic field Hb acting perpendicularly to the chip CHI surface is H2-CO8θ.

Now, since the above-mentioned holding field HdC always acts on the xy plane of the chip CHI, the 29th
As illustrated in FIG. B, the rotating magnetic field Hr' acting on the chip CHI is eccentric. In the figure, Hr is a rotating magnetic field applied from the outside, and Hr' is a rotating magnetic field acting on the chip CHI. In this case, the rotating magnetic field Hr' acting on CHI is a combination of the rotating magnetic field Hr applied from the outside and the in-plane component Hdc, and the rotating magnetic field Hr'
The center O' moves in parallel in the +X-axis direction, which is the start/stop (St/Sp) direction, by an in-plane component Hdc.

Therefore, as is clear from the results in the same figure, even if the strength of the externally applied rotating magnetic field Hr is l Hr 1, the strength of the rotating magnetic field that effectively acts on the chip CHI is
'l varies depending on the phase of the rotating magnetic field Hr. That is, S
lHr'l in the t/Sp direction is 1Hrl+1Hdcl
Therefore, compared to IHrl, holding field H
The strength of dc is increased by IHdcl. On the contrary, St.
/Hr'l in the opposite direction to SP direction is l Hr l
-l Hdcl, which is weaker by 1 Hdcl compared to 1 Hrl.

(Peripheral circuit Fig. 30) Finally, the peripheral circuit of chip CHI will be explained with reference to FIG.

RF is a circuit for generating a rotating magnetic field Hr by passing currents with a phase difference of 90° through the X and Y coils of the chip CHI.

SA is a sense amplifier that samples, senses, and amplifies a minute bubble detection signal from the magnetoresistive element of the chip CHI in synchronization with the timing of the rotating magnetic field. DR is MB
This is a drive circuit that causes current to flow at a predetermined timing to each functional conductor of a replicate that is related to bubble generation and swap related to write and read of the M device. The above circuit is synchronized by a timing generation circuit TG so as to operate in synchronization with the cycle and phase angle of the rotating magnetic field Hr.

(Rotating magnetic field distribution characteristics FIG. 31) FIG. 31 shows the rotating magnetic field distribution characteristics of the magnetic circuit PFC described above. That is, in the figure, the horizontal axis represents the length in the X-axis direction with the center of the magnetic circuit PFC shown in FIG. 8B as O, and the vertical axis represents the rotating magnetic field strength Hx in the X-axis direction.
When the rotating magnetic field strength Hx in the X-axis direction when = O is shown, a rotating magnetic field distribution characteristic as shown by the curve ■ was obtained.

As is clear from the figure, a substantially uniform rotating magnetic field strength Hx is obtained within the range of -Xc to +XC between the opposing cores COR of the magnetic circuit PFC, and
Effective area of HI (minimum range to which rotating magnetic field should be applied) -
In the range of Xs to +Xe, a magnetic field strength uniformity of about 2% was obtained. Note that the curve (2) indicated by a broken line is the rotating magnetic field distribution characteristic due to the magnetic circuit of the conventional configuration.

(Modifications) Although the details have been described above in relation to the overall structure of the magnetic bubble memory shown in FIGS. 1 and 2, the present invention can be implemented in the following modifications.

FIG. 32 is a diagram showing the overall structure of a modified example in which a solenoid coil SOC for measuring the holding magnetic field is added. The SOC is a solenoid coil wound around the outer surface of the case RFS. By press-forming from the top and bottom directions, the case RF
It is arranged in close contact with the shape along the outer surface of S.

FIG. 33 is a diagram showing the solenoid coil SOC, in which figure A is a plan view and figure B is a 33B-33B sectional view thereof. In the figure, the solenoid coil SOC has a winding 40 whose outer surface is coated with, for example, thermosetting resin as an insulating member, and whose inner diameter is a case R.
After aligning and winding so that the FS assembly can be inserted with sufficient dimensional tolerance and the overall shape is a rectangular cylinder,
The coil assembly 41 is formed by thermally welding the coils to each other, cooling them, and forming them into a coil bobbin shape having a predetermined value.

FIG. 34 shows a sectional view of the case RFS assembly described in FIG. 13 incorporating the above-mentioned solenoid coil SOC, magnet body BIM, and bias coil BIC. In the same figure, the coil assembly 4 is inserted into the case RFS assembly which houses the board assembly BND and the magnetic circuit PFC inside, and is press-molded from above and below to form the solenoid along the outer surface shape of the case RFS assembly. The coil SOC is arranged in close contact with each other. Further, an upper magnet body B I M a and a lower magnet body BIMb are adhesively arranged on the upper and lower surfaces of this solenoid coil SOC, respectively.

When measuring the start/stop characteristics of a magnetic bubble memory device configured in this way, first the magnetic bubble memory device is driven, and a rotating magnetic field confinement case RFS assembly is placed on the outer surface of the rotating magnetic field confinement case RFS assembly that houses the chip CHI inside. The third solenoid coil SOC
A direct current Id is simultaneously applied in synchronization with the rotating magnetic field generating current Ir as shown in FIG. This allows case RF
A DC magnetic field H due to the DC current Id is superimposed and applied to the surface of the chip CHI housed in the S assembly together with the rotating magnetic field Hr. In this case, the DC magnetic field H is confined within the case RFS and is generated as a demagnetizing field parallel to the surface of the chip CHI and in the opposite direction to the holding magnetic field Hdc. Therefore, by gradually increasing the DC current Id and increasing the demagnetizing field by applying it to the extent that the chip CHI malfunctions, the holding magnetic field Hdc in the operating region A of the magnetic bubble memory device is increased as shown in FIG. Since the operating tolerance ΔH can be measured and the set value of the holding magnetic field I-(dc can be obtained from this value, it is possible to easily judge whether the holding magnetic field is appropriate or not.

Note that this solenoid coil SOC only needs to obtain a magnetic flux of up to about 100 e, so the winding thickness may be thin, and this does not impede the reduction in thickness and size of the magnetic bubble memory device.

Further, although the solenoid coil SOC is disposed outside the case RFS assembly, the same effect as described above can be obtained even if the solenoid coil SOC is disposed inside the case RFS assembly.

〔Effect of the invention〕

As explained above, according to the present invention, a magnetic bubble memory element mounted on a flexible wiring board is disposed in the space of a rotating magnetic circuit of a frame-shaped core, and the entirety is confined in a rotating magnetic field of a highly conductive material. By sandwiching it in a case and installing a solenoid coil on the outer surface of the case and electrically connecting the periphery, the space in which the leakage magnetic field is generated can be made smaller, so a highly uniform rotating magnetic field can be obtained with a small VI product. In addition, by making the rotating magnetic field confinement case smaller, power consumption is reduced, and the overall shape is smaller and thinner, making it possible to obtain a magnetic bubble memory device that reliably guarantees the start-stop characteristics of the magnetic bubble. Extremely excellent effects can be obtained.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view showing the entire magnetic bubble memory device according to the present invention, FIG. 291A is a bottom view, and FIG. 2B
is a 2B-2B sectional view of Figure A, Figure 3 is an exploded perspective view showing the stacked structure, Figure 4 is a diagram explaining the board FPC, and Figure 5 is a board assembly BND in which the chip CHI is mounted on the board FPC. 6 is a plan view showing the chip CHI,
Figure 7 is a diagram explaining lead bonding of the board assembly BND, Figure 8 is a diagram explaining the magnetic circuit PFC, Figure 9 is a diagram explaining the manufacturing method of the magnetic circuit PFC, and Figure 10 is the inner case. FIG. 11 is a diagram showing the outer case RF S a, FIG. 12 is an assembly diagram of the case RFS, and FIG. 13 is an assembly diagram in which the board assembly END and the magnetic circuit FPC are housed in the case RFS. 14 is a diagram illustrating the configuration of the magnet BIM, FIG. 15 is a diagram illustrating the bias coil, and FIG. 16 is an assembly in which a pair of magnet BIM and bias coil BIC are incorporated into the case RFS assembly. Three-dimensional sectional view, FIG. 17 is a diagram showing the outer shield case SHI a, FIG. 18 is a diagram showing the inner shield case 5HIb, and FIG. 19 is a diagram showing the shield case SHI
FIG. 20 is a sectional view of the assembly shown in FIG. 16 incorporated into the shield case SHI. 21st
The figure shows the packaging case PKG, Figure 22 illustrates the configuration of the terminal fixing plate TEF, Figure 23 illustrates the configuration of the contact pad, and Figure 24 illustrates the chip CHI.
25 is a diagram showing the configuration of the magnetic bubble detector of the chip CHI, FIG. 26 is a diagram showing the configuration of the magnetic bubble generator GEN of the chip CH engineering, and FIG. 27 is a diagram showing the configuration of the magnetic bubble detector GEN of the chip CH.
FIG. 28 is a diagram showing the configuration of the swap gate SWP of chip I, FIG. 28 is a diagram showing the configuration of the replicate gate REP of chip CH and I, FIG. 29A is a diagram showing the relationship between the bias magnetic field Hb and the holding magnetic field Hdc, and FIG. 30 is a diagram showing the total rotating magnetic field Hr', FIG. 30 is a diagram showing the entire circuit of the magnetic bubble memory board, and FIG. 31 is a diagram showing the distribution characteristics of the rotating magnetic field. Fig. 32 is a diagram showing the overall structure of a modified example in which a solenoid coil SOC for measuring the holding magnetic field is added, Fig. 33 A and B are diagrams showing the plane and cross-sectional structure of the solenoid coil SOC, respectively, and Fig. 34 is a solenoid coil. S.O.
FIG. 35 is a waveform diagram of the current flowing through the solenoid coil SOC, and FIG. 36 is a diagram showing the bias magnetic field margin thereof. CHI...magnetic bubble memory chip (element), FPC
...Flexible wiring board (board), BND...board assembly, COI...drive coil (coil), COR
...Picture frame-shaped core (core), PFC...magnetic circuit, R
FS...Rotating magnetic field confinement case (case), RFS
a...Outer case, RFSb...Inner case, BI
M...Magnet for generating bias magnetic field (magnet), BIM
a... Upper magnet body, BIMb... Lower magnet body, ■N
M... Inclined plate, MAG... Permanent magnet plate (magnet plate)
, HOM...Magnetic adjustment plate, INN...Nonmagnetic inclined plate, B
IC...Bias magnetic field generation coil (bias coil), SHI...External magnetic shield case (shield case), 5HIa...Outer shield case, 5HIb
...Inner shield case, PKG...Packaging case, TEF...Terminal fixing plate, GNP...Contact pad, 1...Element mounting section, 2,2. a, 2b
. 2c, 2d - folds, 3.3a, 3b. 3c, 3d...external connection terminal connection section, 4.4-a. 4b---Opening, 5, 5'a, 5b, 5c..."perforation, 6...Substrate protrusion, 7...Base film, 8
...adhesive, 9a...wiring lead, 9b...external terminal, 9c...connection terminal, 9d...symbol, 9e
... index mark, 10 ... cover film, 11 ... tin plating layer, 12 ... opening, 13 ...
Hand plating layer, 14... Ponding pad, 15.
・・Gold bump, 20a, 2ob, 20c, 2od...
Helix coil, 21a, 21b... connection point, 22
a...X coil, 22b--Y coil, =63- 23...Magnetic core, 24...Tap, 25...Wide groove, 26...Small width groove, 30... ...Aperture part, 31...Bending part, 32...Notch part, 33
... Squeezed part, 34... Bending part, 35... Notch part, 36... Polyimide film, 37... Adhesive, 38... Coil winding, 40... Winding wire, 51...
・Flat part, 52... Bent part, 53... Concave part, 5
4... Notch part, 55... Flat part, 56... Bent part, 57... Recessed part, 58... Notch part, 59...
... recess, 60 ... resin plate, 61 ... through hole, 62
...Non-through hole, 63...° mark, 64...Opening,
65... Groove, 66... Corner, 70... Piece, 71
...Nickel plating layer, 72...Gold plating layer. D R HibO Figure 14A Figure 14B Figure 14C =793- Figure 15A Figure 15B Figure 17A Figure 22A Figure 22B cL August 26, 1985

Claims (1)

[Claims] A magnetic bubble memory element mounted on a flexible substrate is disposed in a space formed by a frame-shaped core coiled so that sets of opposing windings are parallel to each other, and the coil, core, and magnetic bubble memory element are mounted on a flexible substrate. A magnetic device characterized in that the entire element is sandwiched within a case made of a good conductive material, and a solenoid coil for applying a direct current magnetic field parallel to the surface of the magnetic bubble memory element is disposed near the case made of a good conductive material. bubble memory.