JPS61248283A - Magnetic bubble memory device - Google Patents

Abstract

PURPOSE:To improve the uniformity of a rotating magnetic field by constituting a core wound by a coil and a rotating magnetic field confining case approximately symmetrically about a shaft vertical to an element surface of a magnetic bubble memory chip. CONSTITUTION:Since recessed parts formed by drawing parts 30, 33 are formed on outer and inner cases RFSa, RFSb to reduce a gap between the opposed recessed parts, a rotating magnetic field is formed only by a horizontal compo nent because a component vertical to the plane of the chip CHI becomes adja cent to zero, so that the uniformity of the magnetic field can be improved. In addition, magnetic circuits PFC, RFS are approximately symmetrical about the shaft vertical to the element surface of the chip CHI. Consequently, the uniformity can be further improved.

Description

[Detailed description of the invention] [Field of application of the invention] The present invention relates to a magnetic bubble memory device, particularly a thinner one.

This invention relates to a magnetic bubble memory device suitable for improving ease of assembly and reducing power consumption.

[Background of the invention]

The magnetic bubble memory device that has been put into practical use in recent years is the magnetic bubble memory chip! An X-coil for rotating magnetic field generation, consisting of a rectangular curved-tip noid coil with an asymmetrical structure on a rounded figure-8-shaped wiring board made of ceramic or synthetic resin.

It has a structure in which each X coil is inserted and arranged orthogonally. The X coil and Y:I 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 the length from end to end of each coil is long, reducing drive voltage and power consumption. It gets bigger. In addition, since the X coil and the X 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, 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. In addition, these X coils,
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 surface of the Y coil, and their peripheral parts are covered with a resin mold. The vertical stacking thickness has increased, which has been an obstacle to the desire to make magnetic bubble memory devices thinner and more compact.

The closest prior art to the present invention known to the applicant is JP-A-54-55129.

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. Possible and permanent magnet,
Including the fact that it is unclear how to attach the magnetic shunt plates, bias coils, etc., the description is clearly insufficient for people to think about putting it into practical use. 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 device that can be made thinner.

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

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

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

Another object of the present invention is to provide a magnetic bubble memory device that has improved assembly of components and allows or facilitates automation.

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

Still another object of the present invention is to provide a magnetic bubble memory device with improved uniformity of a rotating magnetic field.

[Summary of the invention]

According to one embodiment of the present invention, a drive magnetic circuit using a picture frame core is provided. The magnetic bubble memory chip is placed on the flexible wiring board so as to be surrounded by and substantially flush with the frame dust 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. Such a configuration improves the uniformity of the rotating magnetic field and reduces the overall size.
It can be made 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 one embodiment of the magnetic bubble memory device according to the present invention, and Figure 1 is a partially cutaway perspective view. 2A is a bottom view thereof, and FIG. 2B is a sectional view taken along line 2B-2B of FIG. 2A. In these figures, CHI is a magnetic bubble memory chip (hereinafter referred to as a chip), and in these figures, the chip α is omitted and only one chip is shown, but in this example, two chips are arranged side by side. It is assumed that there is (Rather than a single large-capacity chip, a multi-divided chip configuration that matches the total memory capacity has a better chip yield.) The FPC is equipped with two chips CHI, and is connected externally to the 1,000-inch chip in each of the four corners. This is a flexible wiring board (hereinafter referred to as a board) having a wire group extension for connection to a terminal.

The COI surrounds the two chips CHI on almost the same plane and is a drive coil (hereinafter referred to as a coil) arranged so that the opposing sides are parallel to each other, and the COR penetrates the hollow part of the rectangular coil assembly COI. This is a frame-shaped core (hereinafter referred to as core) made of soft magnetic material fixedly arranged as shown in FIG.
It constitutes a magnetic circuit PFC that applies a rotating magnetic field in the k-plane.

US is the center square part of the board FPC and two chips Q
-II and a rotating magnetic field confinement case (hereinafter referred to as the case) that houses the entire magnetic circuit PFC. The case RIFIS is formed by processing two independent plates, and the upper and lower plates are electrically connected at the side of the case. These case boxes F8 have a constriction part formed around the periphery so that the gap in the center part is narrow (in a slightly wider area than the part where the chip CHI is arranged). It can also be used for positioning.

Case F8 has the effect of confining the rotating magnetic field and mechanically supporting the weak FPC board, killing two birds with one stone.

In particular, there is a chip C between the case RF8 and the chip CHI.
There is a gap 811 (,) on the side of the HI, but the chip CHI
This gap portion 8I, including the flat surface of the chip, is coated or filled with silicone resin to prevent foreign matter from adhering to the main surface of the chip during assembly, and to prevent moisture from entering the main surface or side surfaces of the chip after assembly. (This is intended to provide a padding effect.) If a complete hermetic seal can be achieved on the outside of the case RPS, filling with resin 8I may be omitted.

INM is a pair of inclined plates made of magnetic material arranged outside the case RIF'8, and in FIG.
As M moves to the left, the lower inclined plate INM becomes thicker as it moves to the right.
A 1 mK slope is formed. As the material for the inclined plate INM, soft ferrite, permalloy, or the like, which has a high magnetic permeability μ and a small retention cal, may be used, and in this embodiment, soft ferrite, which is easy to process into an inclined surface, is selected. M
AG is a pair of permanent magnet plates (hereinafter referred to as magnet plates) arranged inside the pair of inclined plates INM and overlapping them.

The ROM is a pair of magnetic shunt plates made of a magnetic material such as soft ferrite and arranged inside and overlapping each of the magnet plates MAG. The magnet plate MAG is formed to have a uniform thickness over the entire surface. INN is a pair of magnetic shunt plates H
A pair of inclined plates made of a non-magnetic material with good thermal conductivity, such as copper, are placed on the inner facing surfaces of the OM and stacked thereon. 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. When the inclined plate INM, the magnet plate MAG, the magnetic shunt plate HOM, and the inclined plate INN are arranged in a stacked manner and integrated to form a bias magnetic field generating magnet body BIM (hereinafter referred to as a magnet body), a laminated plate magnet body is formed. The entire thickness is formed to be uniform over almost the entire surface. A pair of magnet bodies BIM are adhered to the central flat part surrounded by the constriction part of the case box FS.

BIG is a bias magnetic field generating coil (
(hereinafter referred to as bias coil). The bias coil BIC adjusts the magnetic force of the magnet plate MAG to match the characteristics of the chip CHI, and when testing for the presence or absence of unnecessary bubble generation, it clears all bubbles on the chip CHI.
It is driven when

8HI is an external magnetic shield case (hereinafter referred to as "shield") consisting of a case RF8 that houses a substrate FPC on which the chip CHI is mounted and a magnetic circuit PFC, and a magnetic material that houses a pair of magnets BIMa and BIMb and a bias coil BIC on the outside of the case RF8. case). The material for the shield case 8HI is preferably a magnetic material with a high magnetic permeability μ, a large saturation magnetic flux density Bs (and a low Hc), and permalloy and ferrite have such characteristics, but in this example, bending Permalloy, an iron-nickel alloy, was selected because it is suitable for machining and is strong against external mechanical forces.

PKG is a packaging case made of a red-like material that has high thermal conductivity and is easy to process, and is attached to the outer circumferential surface of the shield case 8HI by adhesion or fitting. The CNPs are contact pads extending from the four corners of the substrate FPC and arranged so as 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. RIG is I (resin molding V sealed in the four inner corners of the packaging case PKG and fixing the shield case 8HI assembly inside the packaging case PKG)
It is a drug.

(Features of the overall structure, FIG. 1.2) 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 FIG. The main features will be described.

(1) Since the magnetic circuit PFC for generating a rotating magnetic field is shaped like a picture frame, and the bubble memory chips CHI are arranged on the same plane, the thickness of the entire bubble device can be reduced. With current mainstream technology, X on the top and bottom of the chip
This is because the thickness of the entire device is the sum of the chip thickness, the X coil thickness, and Y: the film thickness because the device is wound around the X coil and the X coil.

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

■The wire 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.

■The distance between the X coil and Y: I coil and the tip α can be made equal, and the magnetic field distribution can be balanced (
- on-board improvements).

(51 Magnetic circuit PFC for generating rotating magnetic field is installed in case 8F8.
Since it is surrounded by , there is less leakage of magnetic flux and the drive efficiency for the chip CHIk can be increased.

(4) Case RF8 has a coil C for generating a rotating magnetic field.
It prevents the alternating current magnetic field generated from the OI from leaking to the magnet body BIM with a large magnetic permeability μ, and on the other hand, substantially prevents the passage of the direct current magnetic field of the bias magnetic field Hb to be applied from the magnet body BIM to the chip CHI. There is an option not to.

(5) Since the case RF8 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, [especially when a multi-chip mounting configuration is used for reasons such as increasing manufacturing yield, the variation in the inclination angle between chips has a large effect on the magnetic %Note, but according to this example, the variation between the chips Variations in inclination angle can be suppressed to a small level.

(6) 7 lexiple wiring board FPC as 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 effects of ■ and ■ above are due to the magnetic circuit gear, pu (magnetic permeability μ
It is possible to use a magnet plate MAG with a small thickness or a small plane area, which leads to a thinner device or a reduction in the plane area of the entire device.

■Wiring from the chip CHI can be bent freely. Therefore, the terminal portion 190' can be turned over, 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 FPC board is concentrated at the corners of the rectangle, the opening of the rotating magnetic field confinement case FS can be provided at the corner where the influence is least.

(8) Since the function of the inclined plate INN is not combined with the magnet or magnetization function, the following effects are obtained.

■ Materials such as copper that are easy to work with can be used to form the slope.

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

■By using non-magnetic material, magnetic shunt plate HO
k so as not to disturb the magnetic field passing through M.

(9) In order to reduce the magnetic gap, it is preferable that the inclined plate INN be as thin as possible, and its width should be determined by the magnetic plate M.
Compared to AG and magnetic shunt plate HOM k, the vibration is suppressed to the area necessary and sufficient to form the tilt angle, making it easier to form the tilt angle with a thinner thickness.

(10) Between the magnet plate MAG and the shield case aHI, there is a sloped plate I such as soft zerite with a large magnetic permeability μ.
Since NM is inserted, the magnetic gap between them can be filled. The plate INM also contributes to heat radiation. Since a material having a smaller coercive force Hc than that of the magnet plate MAG is selected for the plate INM, the effective thickness of the permanent magnet can be kept uniform.

(11) Shield case 8HI has a large magnetic permeability μ (I(
-Since it is made of magnetic material such as MAQUI, the magnetic plate MA
Since the magnetic resistance of the magnetic circuit using G as the magnetic field source can be reduced, the thickness and planar area of the magnet plate MAG can be reduced.

(12) Since the shield case 8HI is made of a magnetic material such as permalloy with a high saturation magnetic flux density Be, it has the function of bypassing external magnetic field noise and preventing it from being transmitted to the chip CHI.

(19 above (11) I (1) each leads to reducing the thickness of the shield case SH1.

(14) Since the shield case 8HI is made of an iron-nickel alloy such as permalloy, it is suitable for bending and protects the parts built into it from external mechanical forces.

(15) Since the magnetic circuit PFC for generating a rotating magnetic field and the bias coil BIC are both core-type, case RF8
, 8HI or PKG can increase storage efficiency or packaging density.

(16) There is a case R between the core COa and the magnetic shunt plate HOM.
Since the FS is inserted, the interval can be finely adjusted by adjusting the thickness of the rotating magnetic field confinement case F8 and the bending angle in addition to the thickness of the coil COI.

The shorter this distance is, the smaller the overall planar size t can be, which leads to lower power consumption by reducing the coil length. However, if the distance is too short, the DC bias magnetic field from the magnet plate MAG will leak to the core COR, which has high magnetic permeability, resulting in poor uniformity of the bias magnetic field around the chip. The distance is very severe due to the above characteristics, and this structure allows for precise adjustment of the 0 (17) rotating magnetic field confinement case RF8.
Since a constriction portion is provided around the magnet, alignment of the magnet BIM is easy.

(1B) Two inclined plates INN made under the same manufacturing conditions are arranged so that there is a rotation angle difference of 180@ between the upper and lower surfaces of the chip. A pair of magnetic shunt plates ROM and a pair of magnets M
AG can be aligned almost parallel.

(Overview of assembly, Figure S) Figure S is an assembly perspective view for explaining the procedure for stacking and assembling each of the components 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 assembly B is shown in which two chips CHI are mounted on a board FPC that has connection parts for input/output wiring and has a chip mounting part in the center, protruding from the four corners.
After placing the ND in an outer case RFaa with an insulating sheet 56 adhesively arranged on the bottom surface and incorporating a magnetic circuit PFC on this board FPC, a silicone resin SIR (
(not shown), and the inner case box F8b is assembled into the outer case RP8a IIC on the top thereof, and the side surface contact portions of the outer case RF8a and the inner case box F8b are electrically connected by soldering or the like.

Next, these outer case RFS a and inner case B
, after arranging the upper magnet body BIMa and the lower magnet body BIMb in the concave aperture provided on the outer surface of F8b,
The outer edge of this upper magnet body BIMa and the inner case RF8b
A bias coil BIC wound in an aligned manner is placed in a gap (not shown) formed between the inside of the case 5HIa and the outer shield case 5HIa. The side surface contact portion with case 8HIb is magnetically connected by welding or the like.

Next, the external connection terminal connection parts of the board FPC protruding from the four corners of the shield case 8HI are folded back to the back side of the inner shield case 5HIb as shown in FIG. Each external connection terminal k covered with solder or the like provided in each of these connection parts and a terminal fixing plate TEF with a contact pad GNP mounted in each opening are placed in contact with each other and connected to each external connection terminal by thermocompression bonding or the like. Contact pad GNP is electrically connected by soldering or the like.

Next, these assemblies are stored in the packaging case PkG, and the terminal fixing plate 'I'll? The contact area between the packaging case PKG and the packaging case PKG is sealed using a hermetic seal or the like.

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

(7 Lexiple Si board 〆Figure 4) Figure 4 is a diagram showing the board FPCy, Figure A is its plan view, Figure B is the connection part of the external connection terminal protruding from the four corners ρ1 is folded back and assembled. The arranged plan view, the same figure C is the 4e-4CC enlarged view of the same figure A, the same figure is the aD of the same figure A
-40 is an enlarged sectional view. In the same figure, the substrate F1'C
has a square chip mounted @1 in the center and small bent parts 2 (2a, 2b, 2C,
2d), and a square external connection terminal connection part (hereinafter referred to as a connection part) 5 (5a, 5b, 5c, 5
d), and is integrally formed with the overall shape of a windmill, and two chips CHI, which will be described later, are mounted on opposite sides of the chip mounting section 1, and their terminals are connected to each other. A rectangular opening a (aamab) with a double frame structure that connects the parts.
and 5 perforations 5 (5a, 5b, 5c) for positioning
Further, a board protrusion 6 for positioning is provided at the tip of one connection part 5C.@ Also, as shown in FIG. By forming a copper thin film on the base film 7 made of a resin film via an epoxy adhesive 8 and etching it into a desired pattern shape, wiring leads 9a as shown in the figure AVc are formed.
, a circular external terminal 9b, an elliptical coil lead connection terminal 9C, a symbol 9d, and an index mark 9e. A light or semi-transparent cover film 10 is adhesively arranged.

In the opening 4 of this substrate FPC, an opening is formed with highly accurate dimensions in the base film 7 on the chip CHI mounting side (not shown), and a relatively large opening is formed in the cover film 10 on the upper surface side. is formed,
Further, a wiring lead 9a is exposed between the base film 7 and the cover film 10, a tin plating layer 11 is formed on the surface of the wiring lead 9a, and the opening shape has a two-layer structure and a double-frame structure. It is formed with

On the other hand, in the connecting portion 5, as shown in the figure, a circular opening 12 is formed in 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
b, 9c A solder layer 15 is formed on the copper thin film pattern by plating or dipping. The external terminals 9b and 9c provided in these connecting portions 5 are connected to the connecting portions 5a and 5b.

5c, 5d and bent portions 2a, 2b,
2c, 2d and each wiring lead 9a formed continuously on the chip mounting part 1, and these wiring leads 9a are connected to each opening 43 provided in the chip mounting part 1.
Each connection part 5a, 5b,
5c e 5d are gathered in blocks, and the tips thereof are each opening 4a.

VciB in 4b is output. That is, as shown in FIG. 5A, the wiring lead 9a of the connecting portion 5a is placed at the upper left of the opening 4a, the wiring lead 9a of the connecting portion 5b is placed at the lower left of the opening 4b, and the wiring lead 9a of the connecting portion 5C is placed at the lower left of the opening 4b. 9a is wired to the upper right of the opening 4a, and the wiring lead 9a of the connection portion 5d is wired to the lower right of the opening 4b.

Then, this board FPC is connected to each connecting portion 5 in a process described later.
a, 5b, 5c, 5d are each bent portion 2a
, 2b.

Each external terminal 9b is bent at 2c and 2d and combined as shown in FIG. 2B to form a solder layer 1S.

9C is exposed on the surface, and wiring lead 9a, symbol 9
d and the index mark 9e are covered with the cover film 10, so that these patterns can be easily read through the cover film 10.

In such a configuration, the substrate FPC is made of a polyimide resin film, and each connection part 5a, 5b, 5c, 5d is provided at the four corners of the chip mounting part 1 via each bent part zae2bg20#2a. Each of these connecting portions 5a, 5b, 5c
, 5d is folded back and combined to form the external terminal section.

Since the chip mounting part 1 and the connection part have a two-layer wiring structure,
The chip mounting area 1 can be easily integrated without reducing the area of the connecting area
The zero area can be increased, and at the same time, the number of external terminals can be increased, and the overall shape can be reduced.

Further, in such a configuration, the wiring leads 9a from each external terminal 9b to each opening 4a, 4b of the chip mounting section 1 can be significantly shortened, so that the influence of external noise etc. can be significantly reduced.

That is, signals with a high 87N ratio can be input and output. Furthermore, by providing a board arrow 1@S6 at one end of the connecting part 5C and providing an index mark 9e on this protruding part 6, the case box FS and 8HI (No. (See Figure 2)
Since it is easy to use for positioning when assembling the wiring lead 9a, distinguishing the type of wiring lead 9a, or displaying the product model, it is possible to streamline assembly, board management, etc. Additionally, holes 5a and 5b are provided at both ends of the chip mounting portion 1 of the FPC board.

By providing 5c, it becomes easy to distinguish between the left and right sides of the board FPC, position the chip CHI, etc., and it is also possible to streamline assembly.

(Substrate assembly No. 5 = 6 m Figure 7) Figure 5 shows a plan view of the chip CHI mounted on the aforementioned substrate FPC. In the figure, 2@1 chips CHI are mounted in the chip mounting part 1 of the FPC board through openings 4a and 4b.
A board assembly BND is configured by being mounted in parallel between the two chips, and one of the chips CHI is configured by integrating two chips of IMb, as shown in an enlarged plan view in FIG. With 2 chips CHI, 4 blocks, total 4Mb
It makes up the chip. Note that the chip C shown in FIG.
In one block of HI, thick lines indicate conductor patterns and thin lines indicate chevron pattern transfer paths. In addition, the chip CHI shown in FIG. 5 has each bonding pad 1 provided with a metal fitting Φ at the end of the chip CHI, as shown in the enlarged cross-sectional views of FIG. 7A and FIG. 7 BVC, respectively.
4 and the wiring lead 9a on which the tin plating layer 11 of the substrate FPC opening 4 is formed, gold bumps 15 are interposed, and lead bonding is carried out using Au-Sn eutectic using thermocompression bonding. .

According to such a configuration, the openings aa of the substrate FPC,
The ab wiring lead 9a and the bonding pad 14 of the chip CHI are connected by lead bonding using Au-8n eutectic, and the chip CHI can be supported and fixed, so the connection strength can be greatly improved and the thickness can be reduced. becomes. In addition, since the surface of the chip CHI is covered by the chip mounting part 1 of the FPC board, the surface of the chip CHI is protected, the handling property can be improved, and the mechanical strength of the FPC board 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 block is connected to its closest connecting portion SR, 5b.

Wiring can be distributed to 5c and 5d, and symmetry of chip CHI arrangement can be obtained, making testing, inspection, etc. extremely easy.

Furthermore, the board FP (, &C4 connection parts 5a, 5b
.

5c and 5d, the wiring for the magnetic puzzle detector DEF and pine group of each handpiece CHI can be distinguished from other functional wiring and concentrated in one connection part (6th
(see figure), by selecting and arranging this connection at a location away from the noise source, input/output signals with extremely low noise can be exchanged.

(Driving magnetic circuit FIG. 8.9) FIG. 8 is a diagram showing the magnetic circuit PFCi, where A is a perspective view and FIG. B is a plan view showing the driving magnetic circuit. In the same figure, the magnetic circuit PFC consists of four sets of coils 20a and 20b wound in the direction of the arrows on mutually parallel opposing sides of a frame-shaped core COa made of a soft magnetic material.
A coil COI consisting of , 20C and 20d is wound,
Coils #2Qa and 20b on opposing sides are wound in series via a connection point 21b to form an X coil 22a, and coils 20c and 20d are wound in series via a connection point 21a to form a Y coil 22b. are doing. and,
By supplying currents Ix and Iy (for example, triangular wave currents) with phases different by 90 degrees to the X coil 22a and the Y coil 22b, a leakage magnetic field Hx is generated in the X-axis direction and a leakage magnetic field is generated in the y-axis direction, as shown in aB. H7 is generated and supplied as the above-mentioned two chip CHIk rotating magnetic fields.

Further, in the magnetic circuit PFC configured in this way, 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 20g and 20b, a wide groove 25 having a constant width and a narrower groove 26 are formed by cutting, and then After that, the small width #126 part is cut out, and the wide two parts 11125 are combined and glued together in directions perpendicular to each other to form 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 25 previously formed in the wide groove 25 and the narrow groove 261 described above. . 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 25 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. Furthermore, since the magnetic circuit PPC 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 Figures 10, 11, and 12) Figure 10 is a diagram showing the inner case RF8b, in which Figure A is a plan view and Figure B is a 1oB-1oB sectional view thereof. In the figure, the inner case RF8b includes a frame-shaped constriction part 50 whose central part is concave, and a bent part 51 whose opposing end side is bent upward by approximately 90 degrees.
Each of its four corners has a notch S2 cut diagonally.
, F8b are formed by pressing a highly conductive material, for example, an oxygen-free steel plate. In this case, the constricted portion 50 and the bent portion S1 can improve the mechanical strength of the inner case RF8b 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. . In addition, the aperture part SO is in this case Et
The distance between the magnet body BIMb arranged on the outer surface side of F8b and the chip CHI arranged on the inner surface side can be adjusted as appropriate. Note that the notches 52 provided at the four corners are
Each bent part 2a, 2b of the board FPC is placed in this case HFISb.

It forms the drawer parts 2c and 2d.

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

In addition, although oxygen-free copper was used for the inner case R and P8b,
In addition, copper, silver, gold plates, or plated alloy plates of these may be used.

The eleventh factor is a diagram showing an outer case RF8a corresponding to the inner case RF8b described above, where A is a plan view and B is a sectional view taken along line IIB-11B.

In the same figure, the outer case RFSa is formed using the same materials and manufacturing method as the inner case RF8b described above, and its structure is almost the same as described above, including a frame-shaped constriction part 5S with a concave central part, and A bent portion 54 whose opposing end side is bent upward at approximately 90 degrees, and each of the bent portions 54
The corner has a notch 55 cut diagonally. In this case, the bent portions 5 facing each other
4, the inner dimension between them is the inner case R mentioned above.
It is formed to have approximately the same value as the outer dimension between the folded portions 51 of F8b, and to have a larger height H. Note that the constricted portion 55 and the cutout portion 55 are formed to have substantially the same dimensions as the aforementioned inner case RFsb.

FIG. 12 is a plan view of the outer case RF8a and the inner case RFSb, which are constructed as shown in FIG.

As shown in the 12B-12B sectional view in FIG. 12B, by inserting the inner case RFSb into the outer case x RFaa and connecting the outer surface of the bent portion 51 of the outer case RF8a by bringing them into contact with each other, An integrated case box F8 is assembled.

(Case Assembly FIG. 15) FIG. 1S is a sectional view showing the board assembly BND housed in the case assembly described above.

In the same figure, a polyimide film 56 with a thickness of approximately α111 m1 is adhesively arranged as an electrically insulating sheet on the bottom surface of the outer case RF8a, and a board assembly BND is placed on this film 56, and its peripheral edge is A magnetic circuit PFC is arranged in each part, and after applying an epoxy adhesive 57 to the upper surface of the board assembly END,
An inner case RF8b is inserted into the upper part of these and arranged to be joined. In this case, this outer case 几FSa
The inner surface of the bent portion 54 of the inner case uSb and the outer surface of the bent portion 51 of the inner case uSb are electrically and mechanically joined by metal 70 or soldering at a portion indicated by an X mark. Further, the gap between the outer case RFSa and the inner case FSb 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 FPC board are inserted into the not shown notches 52 and 55 provided at the four corners of the outer case F8a and the inner case uSb.
(2a.

zb, 2C, 2d) are drawn out. 5
8 is the connection between coil COI or coil COI and fi
This is a lead wire for connecting 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 PFC, an induced current flows through the case RF8 to form a closed loop, and this induced current confines the rotating magnetic field within the case RFa, thus causing the chip CHI is applied with a uniform rotating magnetic field.

According to such a configuration, the chip CHI mounted on the board FPC is sandwiched between the outer case RF8a and the inner case FLFSb in the concave part of the central part, and the magnetic circuit PFC is held in the convex part of the peripheral part. This arrangement not only improves the packaging effect but also greatly improves the ease of assembly. In addition, by reducing the volume covered by the outer case KFSa and the inner case apsb, the VI product ((volume) can be reduced, and the magnetic circuit M PFC that generates the rotating magnetic field can be made smaller. Furthermore, the outer case RF8a and a throttle part 50 on the inner case RF8b.
, 55 by reducing the gap between the opposing recesses, the rotating magnetic field can be applied to the chip CH
The component perpendicular to the plane of I (Z component) is close to zero and there is only a horizontal component, which can improve the sense of courage. Furthermore, since the magnetic circuit PFC and the case RF8 have a nearly symmetrical structure with respect to the axis perpendicular to the element surface of the chip CHI, -
You can improve your guts even further.

(Magnet Figure 14) Figure 14 is a diagram showing the magnet body BIM, in which the person in the figure is a plan view, the figure B is a side view, and the 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, a magnetic shunt plate HOM with a uniform thickness placed on the slope side of the slope plate 1NN, a magnet plate MAG with a uniform thickness placed on the top side of this magnetic shunt plate HOM, and this magnetic plate MAG. Inclined plates INM having an inclined surface on the upper surface side are sequentially stacked,
It is formed by being integrated with an epoxy adhesive, and is constructed so that the overall thickness of the laminate is uniform over almost the entire surface. A uniform bias magnetic field is emitted from the top and bottom 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, in which the person in the figure is a perspective view, and the figure B is a 15B-15B sectional view thereof. In the same figure, the bias BIC has winding wires 40 whose outer surfaces are coated with, for example, thermosetting resin as an insulating member, and arranged so that the cross section is a 5 x 4 wire arrangement and the overall shape is like a picture frame. After being rolled up, 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
Since the 0s are cured in a bundled state, they are formed into a predetermined picture frame shape.

(Mounting the magnet and bias coil on the case assembly
Figure 16) Figure 16 shows the magnet body BIM and bias coil BIG described above in the case RF8 assembly explained in Figure 15.
This figure shows a cross-sectional view incorporating the.

In the same figure, the top of the case RF8 assembly that houses the board assembly BND and the magnetic circuit PFC inside.

Upper magnet BIMa and lower magnet B are on the bottom surface, respectively.
IMb is adhesively arranged, and this upper magnet body BIMa
A bias coil BI is placed in the frame-shaped groove formed by the peripheral edge of the inner case RF8b and the bent portion 51 of the inner case RF8b.
C is stored.

In this case, the upper magnet body BIMa and the lower magnet body BIMb are entirely made of the same material and dimension, and the inclined plate 1 side of these magnet bodies BIMa and BIMb is the constricted part 50 of the inner case RFSb. They are arranged in close contact with each other in the enclosed concave portion and the concave portion surrounded by the aperture 55 of the outer case RFSa.

In such a configuration, a pair of magnets BIMa are placed in the concave portions formed on both sides of the central portion of the case RFS assembly.
, BIMb is disposed, and the bias coil BIC can be disposed within the frame-shaped groove formed at the periphery of the BIMb, so the overall thickness of each component in the stacking direction is reduced.
It is possible to make it smaller and thinner. In addition, the outer case box F8a
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 Cases Nos. 17, 18, and 19) FIG. 17 is a diagram showing the outer shield case 8HIa, and FIG. 17 is a plan view, and FIG. In the figure, the outer shield case 5HIa includes a flat part 51, a bent part 52 that is folded upward at approximately 90 degrees on the opposite end of the flat part 51, and a part cut out in the center of the bent part 52. The outer shield case 5HIa has a cutout recess 55 and a notch 54 cut diagonally at each of its four corners.
is formed by pressing a material having high magnetic permeability, high saturation magnetic flux density, and preferably high thermal conductivity, such as a permalloy plate.

FIG. 18 is a diagram showing an inner shield case 5HIb corresponding to the above-mentioned outer shield case 8HIa, and FIG. 18 is a plan view, and FIG. In the figure, this inner shield case 5HIb is
It is formed using the same material and manufacturing method as the outer shield case 8HIa described above, and its structure is almost the same as described above, including a flat part 55 and a bent part bent upward at approximately 90 degrees on the opposite end of the flat part 55. 56, a recessed portion 57 partially cut out in the center of the bent portion 56, and notched portions 58 cut diagonally at each of the four corners thereof. In this case, the mutually opposing bent portions 56 have an outer dimension L4 between them that is approximately the same as the inner dimension L4 between the bent portions 52 of the outer shield case 8HIa described above, and the height H is reduced. It is formed at (℃-).

The outer shield case 5HIa and the inner shield case 5HIb configured in this way have an inner shield inside the outer shield case 5HIa, as shown in FIG. 19A as a plan view and as shown in FIG. Insert case 5HIb and remove outer shield case 8H.
Recess 55 of Ia and recess 5 of inner shield case 8HIb
Spot welding or solder welding is performed on the concave portion 59 formed by 7 and 7, and the shield case 8HI is assembled by magnetically and mechanically fixing the shield case 8HI. In such a configuration, by setting the bent portion 52 of the outer shield case 5HIa and the bent portion 56 of the inner shield case 8HIb in the lateral direction, that is, in the direction intersecting the laminating direction, by aligning them with the laminating direction and setting them at °C. By reducing the lateral dimension, it is possible to achieve compactness and high integration of component parts.

(Magnetic shield case assembly jI20) Figure 20 shows the above-mentioned 16th magnetic shield case assembly inside the above-mentioned shield case 8HI assembly.
The case RFS assembly includes the board assembly BND, Wl + air circuit PFC inside as explained in the figure, a pair of magnet bodies BIMa, BIMb, and bias coil BIC.
FIG. 3 shows a cross-sectional view of an assembly including the following. In the figure, inside the outer shield case 5HIa, there is an upper magnet body BIMa extending from the bottom side to the center.
After sequentially stacking the bias coil BIC, case RF'8 assembly (board assembly BND, magnetic circuit PF'C, etc. are incorporated inside), and lower magnet body BIMb on the periphery of m, the inner shield case is assembled. 5HIb is inserted into the recess 5 formed by the recess 55 of the outer shield case 5HIa described above and the recess 57 of the inner shield case 8HIb.
9 (see FIG. 19), it is welded and fixed and sealed. In this case, by filling the shield case 8HI with grease or the like, the internal components will come into close contact with each other, and the heat generated from the case RF8 will be transferred to the outside through the shield case 8HI. can be released to

Furthermore, the heat dissipation effect can be improved by forming the case S and the shield case 8HI into contact with each other at their sides by a press-fitting method.

In such a configuration, the outer shield case 8HIa
Place the case box F8 assembly on the bottom side of the
, 54 are stacked to face each other, thereby forming an outer shield case 8HIa and an inner shield case 5).
Since each component laminated between IIb and IIb can be arranged in close contact with each other, 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) The 21st figure is a diagram showing the packaging case PKG. The case PKG is formed by drawing a material with good thermal conductivity, for example, an aluminum plate with a thickness of 0.5 am, and has a black coating on its outer surface (not shown).This packaging case The PKG can be used in combination with the outer shield case 8HIa by improving its shape.

In such a configuration, this packaging case P
The KG functions 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 hearing aid during resin molding using the botting method, which will be described later. .

(Terminal fixing plate and contact pad Figures 22 and 25) Figure 22 is a diagram showing the terminal fixing plate TEF.
is its rear view. In the same figure, the terminal fixing plate TEF
is made of an electrically insulating material, a multilayered glass epoxy resin plate 60, and is formed using a method,
In addition, except for the peripheral part of this resin plate 60, a large number of through holes 61 are formed in a trix-like arrangement at predetermined intervals in the vertical and horizontal directions, and furthermore, at the corners of these through holes, rotating holes are formed. Non-through hole 62 with a concave cross section that is not symmetrical
A mark 65 such as a white coating film for locating directionality or features is provided in the non-through hole 62.
is attached. In addition, the large number of through holes 61 drilled in the resin plate 60 are provided with large diameter openings 64 coaxially communicating with each other on the back side thereof, as shown in BK of the same figure. All of the openings 64 have a depth of about 60 inches, which is the thickness of the plate, and communicate with the through hole 61 with a step in the middle. Also, on the back side of this resin plate 60, C
As shown in FIG. 2, a groove 65 is formed along its peripheral portion, having a depth substantially equal to the depth of the opening 64, and having a different width in the plane direction and a concave cross section. It constitutes a passage section and a connection section for the winding of the coil COI and the winding of the bias coil BIC. Further, the corner portion 66 of this resin plate 60 does not have a concave shape, but has a predetermined thickness, and provides a contact surface with the inner surface of the packaging case PKG described above. In this way, the resin plate 60
The back side of is formed to have a two-stage structure with different plate thicknesses.

FIG. 25 is a diagram showing the contact pad CNP, where the figure shows a plan view and the figure B shows a cross-sectional view. In the figure, the contact pad CNP is formed by forming a nickel plating layer 71 on the surface of a piece 70 punched out of a highly conductive material, for example, a copper plate with a thickness of about Q and about 5 m by press working. A metal layer 72 is formed.

(Final assembly Figure 20.4.2) Each of the components configured in this way is first placed in the packaging case PKG described above.

Insert the shield case assembly described in FIG. 20.

In this state, each connection part 5a, 5b,
5c and 5d (see Figure 4) are each bent part 2.
It bends at about 90 degrees and protrudes from a, 2b, 2c, and 2d. Next, this packaging case P
Resin molding is performed at the four corners of the PKG by a potting method, and each individual component is fixedly arranged within this packaging case PKG. Subsequently, each of these connection parts 5a,
5b, 5c, and 5d at the corresponding bent portions 2a.
, 2b, 2c, and 2d are further bent at about 90 degrees and assembled to the outer surface of the inner shield case 8HIb with adhesive as shown in FIG. 4B, and then each opening on the back side of the terminal fixing plate TEF is A contact pad ○ is mounted in 64, or a contact pad G is installed in addition.
Fix the sides of the NP with adhesive, insert it into the packaging case PKG, and connect each connection part 5m, 5b, 5C.
, 5dK contact placement. In this case, the dispute connection part 5a,
Since the arrangement pitch of each external terminal 9b provided on 5b, 5c, and 5d matches the arrangement pitch of each contact pad CNP, each external terminal 9blH contacts electrically with the contact pad CNP. Next, each contact pad GNP corresponding to each external terminal 9b is electrically At the same time, the terminal fixing plate 'I'BP is also mechanically fixed at the same time, thereby completing the magnetic bubble memory device shown in FIG.

(Magnetic bubble memory chip No. 24, 25, 26
, 27° and 28) FIG. 24 shows a cross-sectional view of the vicinity of the bonding pad PAD of the magnetic bubble memory chip CHI described above. In the same figure, GGG (gadolininn-ga
11ium-garnet) is the substrate, and L
PE is a bubble magnetic film formed by a liquid 1'4-phase epitaxial growth method, and an example of its composition is shown in Table 1 below.

Table 1 1ON shows the ion implantation layer formed on the surface of the K LPE film to suppress hard bubbles. SPl is the first spacer, for example 8i02 with a thickness of 5000 A'
is formed by a gas phase chemical reaction. CON 1 and CO
N2 indicates a two-layer conductor layer, which has the function of controlling bubble generation, copying (splitting), and exchange, which will be described later.The lower first conductor layer CON1 is Mo, and the upper (1) Two conductor layers CON2 are each formed of a material such as Au. 8P2 and 8Ps are glabellar insulating films (second and fifth spacers) made of polyimide resin or the like that electrically insulate the conductor layer CON and the transfer pattern layer P, such as permalloy, formed thereon. PAS is a padded carbon film made of 5i02a or the like formed by a gas phase chemical reaction method. PAD indicates the bonding pad of the chip CHI, and a thin connector wire such as a wire is bonded here by thermocompression bonding or ultrasonic bonding. This bonding pad PAD has the lower first layer PAD 1 made of Cr.
, the second layer PAD 2 in the center is an Au layer, and the upper fifth layer PA
Ds are each made of a material such as an Au plating layer, and the second layer PAD2 and the fifth layer PAD5 are made of Cr,
It may be formed of a material such as Cu. P indicates a layer used for a bubble transfer path, a bubble division 9 generation, exchange and detection section, and a guardrail 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 and upper layer P 2 KFe-Ni are used, as described above, it is also possible to interchange the two materials vertically.

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. MgD 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 and the like. Although only two stages of bubble stretchers 8T are shown above the main magnetoresistive element MEM, there are several dozen stages of bubble stretchers 8T that stretch bubbles laterally and transfer them downward. Note that PR indicates the bubble transfer direction. ER is a bubble eraser and is erased when the conductor layer CNDK bubble reaches it. A guardrail GR consisting of five rows of pattern groups is provided around this detector and between the dummy and main detection.
It is designed to expel unnecessary bubbles generated inside the guardrail GR to the outside thereof, and prevent unnecessary bubbles generated outside the guardrail GR from entering inside thereof. 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 figure, a magnetoresistive element MEM.

By forming the MED with multilayer magnetic layers, the signal-to-noise ratio (87N ratio) was improved. For example, as a transfer pattern, 8i0. When a 5-layer permalloy layer with J[ interposed therebetween is used, the SZN ratio can be increased by more than twice as shown in Table 2 below, compared to a permalloy single layer.

Table 2 Furthermore, the performance of the guardrail GR is also improved, such as by increasing the removal rate of unnecessary bubbles due to the reduction of the holding force HC.

Figure 826 shows a magnetic bubble generator GffN, and by making the transfer pattern layer P multi-layered, the current generated by the magnetic bubble can be reduced, and the life of the conductor layer CHD of the magnetic bubble generator can be extended. Therefore, a semiconductor element with a small current capacity value can be used in the drive circuit of the conductor 1fli CND, and the cost can be reduced.

FIG. 27 shows a minor loop m formed by a transfer pattern such as Pa-Ph, a write major lie yWML formed by a transfer pattern sequence such as Pw1 to Pw5, and a swap gate portion formed by a hairpin-shaped conductor layer CND. There is. In the same figure, Py is the same as the transfer pattern P7 in the bubble generator GEN in FIG. #/c Transferred. When a current is passed through the swap conductor layer CND, the transfer pattern Pd of the minor loop m1
The magnetic bubbles from major line Pw1 are transferred to transfer pattern Pw5 of major line WML through transfer patterns PL and Pm, and the magnetic bubbles from major line Pw1 are transferred to transfer pattern Pe of minor loose via transfer patterns Pk, Pj, and Pi. Then, bubbles are exchanged, that is, information is rewritten. In addition, the rightmost minor loop ml
does not have a swap gate, but it is a dummy loop that does not inject magnetic bubbles to reduce fringe effects. By multilayering the transfer pattern layer PixPm at the exchange position 5 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 same figure, the normal magnetic bubbles are Pn M-Py, Ps
4 The bubble is transferred along the normal path of Px, and when a current is passed through the conductor layer CND, the bubble is divided at the position of the transfer pattern Pf, and one divided magnetic bubble is Py, Pa to P
It is transferred to the read major line RML via IO.

(Holding magnetic field and rotating magnetic field @Fig. 29) The magnet plate MAG is arranged to be inclined by about 2 degrees relative to the chip CHI. This applies pressure so that the bias magnetic field is applied to the chip CHI k in a direction slightly deviated from the perpendicular direction, thereby creating a holding magnetic field Hdc that improves the start and stop margins of bubble transfer by approximately 6υe (see Figure 29A). ).

As shown in Figure 29 AK, magnet body BIM and chip CHI
Due to the inclination of angle I with , the DC magnetic field Hz has a component Hdc in the xy plane. The magnitude of this in-plane component Hdc is Hdc-sinθ, and normally Hd
The inclination angle should be selected so that c-s inθ=5[)e]-6(Oe). Moreover, this in-plane component Hd
The direction of c is the start and stop of the rotating magnetic field Hr (8t
/8p) direction (+x-axis direction). This xy in-plane component Hdc is a known magnetic field called a holding field, which functions effectively for the start/stop (at/8p) operation of the rotating magnetic field Hr. Note that the magnitude of the bias magnetic field Hb acting perpendicularly to the chip CHI surface is Hz·cos θ.

Now, since the above-mentioned holding field Hdc always acts on the xy plane of the chip CHI, @29
As illustrated in Figure B, the rotating magnetic field Hr' acting on the chip CHIK is eccentric. In the figure, Hr is a rotating magnetic field applied from the outside, and Hr is a rotating magnetic field that acts on the chip CHIK. In this case, the rotating magnetic field Hr' acting on the chip 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 H
The center 0 of r' is translated by an in-plane component Hdc in the +X-axis direction, which is the start/stop (at/8p) direction.

Therefore, as is clear from the results in the figure, even if the strength of the externally applied rotating magnetic field Hr is 1 Hrl, the strength of the rotating magnetic field that effectively acts on the chip CHI is I Hr'
l differs depending on the phase of the rotating magnetic field. That is, St
lHr'l in the /Sp direction is 1Hrl+1Hdcl, and the holding field Hd is smaller than 1Hrl.
The strength of c is 1Hdel. Reverse K, S
lHr'l in the opposite direction to the t/8p direction is 1Hrl
-IHdcl, which is weaker by 1Hdcl compared to 1Hrl.

(Peripheral circuit Fig. 50) 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.

8A 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 a drive circuit that causes current to flow at a predetermined timing through each functional conductor of a replicate that is related to bubble generation and swap related to writing and reading of the magnetic bubble memory device MBM. The above circuit is a timing generation circuit TG that operates in synchronization with the cycle and phase angle of the rotating magnetic field Hr.
It is synchronized by K.

(Rotating magnetic field distribution characteristics FIG. 51) FIG. 51 shows the rotating magnetic field distribution characteristics of the magnetic circuit PFC described above. That is, in the same figure, the horizontal axis represents the length in the X-axis direction with the center 0 in the magnetic circuit PFC shown in FIG. 8B, and the vertical axis represents the rotating magnetic field strength in the X-axis direction =
When the rotational magnetic field intensity wind in the X-axis direction is shown when it is 0, a rotating magnetic field distribution characteristic as shown by curve I was obtained. As is clear from the figure, the distance to the inside between the opposing 37008 of the magnetic circuit PFC -Xc^+Xc f)
ffJ! In addition, in the effective area of the chip opening (minimum range to which a rotating magnetic field should be applied) -Xe to +Xs, a magnetic field strength of approximately ±2 superior can be obtained. It was done. 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.

[Effects of the Invention] As explained above, according to the present invention, a magnetic bubble memory chip mounted on a flexible wiring board is disposed in the space of a rotating magnetic circuit of a frame-shaped core, and the whole is made of a highly conductive material. By sandwiching the magnetic material in a rotating magnetic field confinement case and electrically connecting its periphery, the space in which leakage magnetic fields are generated can be made smaller, and a highly uniform rotating magnetic field can be obtained with a small VI product. , low power consumption is achieved by making the rotating magnetic field confinement case smaller.
And the overall shape is small.

The extremely excellent effect of obtaining a magnetic bubble memory device that is thinner and has an improved assembly ratio can be obtained.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway perspective view showing the whole magnetic bubble memory device according to the present invention, Fig. 2 is a bottom view, Fig. 2B is a sectional view taken along line 2B-2B in the same figure, and Fig. 5 is a stacked structure. Figure 4 is a diagram explaining the board FPC, Figure 5 is an exploded perspective view showing the
The figure shows board assembly B with chip CHI mounted on the board FPC.
A plan view showing the ND, Figure 6 is a diagram showing the chip opening, and Figure 7 is a plan view showing the ND.
The figure is a figure explaining the lead bonding of the board assembly BND, Figure 8 is a figure explaining the magnetic circuit PFC, Figure 9 is a figure explaining the manufacturing method of the magnetic circuit PFC, and Figure 10 shows the inner case RF8b. Figure 11 shows the outer case RF8.
Figure 12 is an assembly diagram of case box F8, 1S
The figure is a sectional view of the assembly in which the board assembly BND and the magnetic circuit PFC are housed in the case RFa, and Figure 14 is the magnet body B.
A diagram explaining the configuration of the IM, Figure 15 shows the bias coil B.
A diagram explaining the IC, Figure #II6 is a cross-sectional view of the case RF8 assembly incorporating a pair of magnets BIM and bias coil BIC, Figure 17 is a diagram showing the outer shield case 5HIa, and Figure 18 is the inner side. Shield case SH
19 is an assembly diagram of the shield case 8HI, FIG. 20 is a sectional view of the assembly shown in FIG. 16 incorporated into the shield case 8HI, and FIG. 21 is an assembly diagram of the packaging case PKG. 22 is a diagram explaining the structure of the terminal fixing plate TEF, FIG. 25 is a diagram showing the structure of the contact pad GNP, FIG. 24 is a cross-sectional view of the chip CHI, and FIG. 25 is a diagram showing the magnetic bubble of the chip CHI. A diagram showing the configuration of the detector, FIG. 26 is a diagram showing the configuration of the magnetic bubble generator GEN of the chip CHI, and FIG. 27 is a diagram showing the configuration of the chip CHI.
Figure 28 is a diagram showing the configuration of SWP (swap game), Figure 28 is a diagram showing the configuration of REP (resilicate game) of chip CHI, Figure 29A is a diagram showing the relationship between bias magnetic field Hb and holding magnetic field Hdc, Figure 29B is a diagram showing the relationship between bias magnetic field Hb and holding magnetic field Hdc. 50 is a diagram showing the total rotating magnetic field Hr, FIG. 50 is a diagram showing the entire circuit of the magnetic bubble memory board, and FIG. 51 is a diagram showing the distribution characteristics of the rotating magnetic field. CHI s magnetic bubble memory chip (Chivpu), FPC
s Flexible wiring board (substrate), BND s Substrate assembly, COI s Drive coil (coil), CUR picture frame core (core), PFC s Magnetic circuit, RFS s Rotating magnetic field confinement case (case), RF8
a1 outer case, FSb1 inner case, BIM s bias magnetic field generation magnet (magnet), B
IMa s upper magnet body, BIMb + lower magnet body, INM s inclined plate, MAG s permanent magnet plate (magnetic plate), HOM s magnetizing plate, INN s non-magnetic inclined plate, BIC, bias magnetic field generation coil (bias coil) )
, 8) II, External magnetic shield case (shield case), 5HIa 1 outer shield case, 5HIb inner shield case, PKG packaging case, TEF s terminal fixing plate, CNP s contact pad, 1S chip mounting part, 2. 2a, 2b, 2C, 2d l bent part, 5.5a
, 5b, 5c, 5d s External connection terminal connection section, 4.4a
, ab, opening, 5.5a, 5b, 5c; perforation, 6s board protrusion, 71 base film, 81 adhesive, 9a wiring lead, 9b s external terminal, 9c s connection terminal, 9d s symbol, 9e recruitment index mark, 10s cover film, 111 tin plating layer, 128 opening, 15s solder plating layer, 14% bonding pad, 15s gold bump, 20a, 20b, 20c, 20d s':Ile 21
a, 21b s connection point, 22a s Notch part, 551 drawing part, 54 folded part, 55 S notch part, 56 S polyimide film, 57 screw adhesive, 58 S coil winding, 401 winding wire, 51 flat part, 521 folded part, 55 small part Recessed part, 54 small notch part, 55 s flat part, 561 cut and bent part, 578 recessed part, 58 rich notch part, 591 recessed part, 60 s resin plate, 61 small through hole, 62 s non-through hole, 65 s mark , 64s aperture, 65s@. 661 corner, 70s piece, 1 nickel plating layer, 72B gold plating layer.

Claims (1)

[Claims] A magnetic bubble memory chip mounted on a wiring board and electrically connected thereto is placed in a position surrounded by two sets of rectangular annular cores each having a wire wound on two opposing sides.
In the magnetic bubble memory device in which the magnetic bubble memory chip, the winding, and the core are covered with a rotating magnetic field confinement case, the rotating magnetic field confinement case is divided into an upper side and a lower side of the magnetic bubble memory chip. Also, a magnetic bubble memory device characterized in that the core having wire winding and the rotating magnetic field confinement case have a substantially symmetrical structure with respect to an axis perpendicular to the element surface of the magnetic bubble memory chip.