JPS61248282A - Magnetic bubble memory device - Google Patents

Abstract

PURPOSE:To improve assembling efficiency and to make automation possible or easy by assembling a rotating magnetic field confining case, magnetic bubble memory chip mounted on a wiring board and a core wound by coils so as to be laminated in a uniaxial direction. CONSTITUTION:Coils are wound around a rectangular parallelepiped magnetic core 23 consisting of a soft magnetic material, plural taps 24 are formed in each block to form an coil 22a consisting of a serially and unitedly wound coils, e.g. a pair of coils 20a, 20b, a wide groove 25 having a fixed width and a narrow groove 26 are engraved between respective coils 20a and 20b, the narrow groove 26 part is cut off to divide the wide groove 25 into two parts, and then respective divided wide grooves 25 are rectangularly combined and adhered to form a magnetic circuit PFC like a frame. Since the coils 20a, 20b are wound around the rectangular parallelepiped magnetic core 23 through the tap 24 in a serial direction, it is unnecessary to intersect and connect these coils, so that the winding of the coils can be simplified.

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.

The present invention relates to a magnetic bubble memory device suitable for miniaturization, low power consumption, and improved assemblability.

[Background of the invention]

Magnetic bubble memory devices, which have been put into practical use in recent years, generate a rotating magnetic field consisting of rectangular tip nodoid coils with an asymmetrical structure on an E-shaped ceramic or synthetic resin wiring board on which a magnetic bubble memory chip is mounted. X coil for corpses.

It has a structure in which each X coil is inserted and arranged orthogonally. The X coil and the In addition, since the X coil and the In addition, these X coils, Y coils
On the outer surface of the coil, a pair of permanent magnet plates that apply a perpendicular bias magnetic field to the magnetic bubble memory element and its magnetic shunt plate are arranged, and the surrounding parts are covered with a resin mold, so that the vertical This increases the stacking thickness in the direction, which has become an obstacle to the demand for thinner and smaller magnetic bubble memory devices.

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

This publication describes the structure of a frame core that surrounds the chip and a conductive magnetic field reflection box that completely surrounds them.

However, no further specific structure is shown, and for example, electrical connections to a chip completely surrounded by a conductor case should not be short-circuited to it from outside the conductor case (this is theoretically possible). It is impossible, and the description is clearly insufficient for anyone 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 present invention The embodiment merely coincidentally coincides with the description in the above-mentioned publication in that a frame-shaped core was 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 improves 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 board core is provided. The magnetic bubble memory chip is surrounded by a frame-shaped core and arranged on a flexible wiring board so as to be 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. 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. shall be taken as a thing. (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 externally connected to the chip α in 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 is a drive coil (hereinafter referred to as a coil) that surrounds the two chips CHI on the same plane and is 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 Vc in-plane rotating magnetic field.

RJS is a rotating magnetic field confinement case (hereinafter referred to as the case) that houses the central rectangular part of the board FPC, two chips CI (I), and the entire magnetic circuit PFC. The upper and lower plates are electrically connected at the side of the case.These cases RFS have a gap in the center that is slightly wider than the area where the chip CHI is arranged. A constricted portion is formed in the peripheral portion. This constricted portion can also be used for positioning the magnet body, which will be described later.

The case RFS has the effect and function of killing two birds with one stone by confining the rotating magnetic field and mechanically supporting the weak FPC board.

In particular, there is a chip CHI between the case uS and the chip α
There is a gap SIR on the side surface of the chip, but this gap (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, or moisture from entering the chip after assembly. The badge page effect is intended to reduce the chance of intrusion into the main surface or side surfaces of the chip. If complete airtight sealing can be achieved on the outside of case RF8, filling with 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. Both have an inclined surface formed on the case RFa side. As the material for the inclined plate INM, soft ferrite, permalloy, etc., which has a high magnetic permeability μ and a small coercive force He, may be used, and in this embodiment, soft ferrite was selected because it is easy to process the inclined surface. M.A.G.
are a pair of permanent magnet plates (hereinafter referred to as magnet plates) arranged inside the pair of inclined plates INM and overlapping them. R.O.
M is a pair of magnetic shunt plates made of a magnetic material such as soft ferrite, which are arranged inside each of the magnet plates MAG and overlap therewith. The magnet plate MAG is formed to have a uniform thickness over the entire surface. INN is a pair of magnetic shunt plates HOM
A pair of inclined plates made of a non-magnetic material with good thermal conductivity, such as copper, are placed on opposing inner surfaces of the magnetic head. 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. 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 the magnet body), when the laminated plate magnet body The entire thickness is formed to be uniform over almost the entire surface. 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 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 RFS that houses the board FPC on which the chip CHI is mounted and the magnetic circuit PFC, and a magnetic material that houses a pair of magnets BIMa and BIMb and a bias coil BIC on the outside. case). As the material for the shield case SHI, a magnetic material with high magnetic permeability μ and large saturation magnetic flux density Bs (and low Hc) is preferable, and permanent magnets and ferrite have such characteristics, but in this implementation 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 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. GNPs 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. 'I'EF is a terminal fixing plate made of an insulating material that supports and fixes each contact pad GNP at the stepped part of the opening.REG is enclosed in the four inner corners of the packaging case PKG and is attached to the shield case 8HI assembly. This is a resin molding agent that is fixed inside the packaging case PKG.

(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 explanation after Figure 5, but here we will focus on the relationship between each component. The features are described below.

(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 substantially the same plane, the thickness of the entire /pull device can be reduced. This is because in the current mainstream technology, the chip is wound around the X and X coils on the top and bottom surfaces, so the thickness of the entire device is the sum of the chip thickness, the X coil thickness, and the Y coil thickness.

(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 on top of 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.

(2) The distance between the X coil and the X coil and the chip CHI can be made equal, and the magnetic field distribution can be made balanced (-machine improvement).

(5) Magnetic circuit PFC for generating rotating magnetic field in case RFS
Since the chip is surrounded by
drive efficiency can be increased.

(4) In case RF8, the AC magnetic field generated from the coil CO for generating a rotating magnetic field is connected to a magnet body BI with a large magnetic permeability μ.
To prevent leakage to M, on the other hand, from the magnet BIM to the chip CH
There is selectivity to the direct current magnetic field of the bias magnetic field Hb to be applied to I so as not to substantially prevent its passage.

(5) Since the case RFS 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 multiple chip mounting structure is used for reasons such as increasing manufacturing yield, the variation in the inclination angle between chips has a large effect on the magnetic properties, but according to this example, the inclination angle between the chips is Variations can be kept small.

(6) Flexible wiring 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 effects of ■ and ■ above are due to the magnetic circuit gap (magnetic permeability μ
It is possible to use a magnet plate MAG- having a small thickness or a small planar area, which leads to a cave-in or a reduction in the planar area of the entire device.

■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 board FPC is concentrated in the corners 1i1 of the rectangle, the rotating magnetic field confinement case F8 (1
) Openings can be provided at the corners where the impact 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 with good workability, such as copper, 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 RO
It can be set to 5 so as not to disturb 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, and its width should be determined by the magnetic plate M
Compared to AG and magnetic shunt plate HOM, by restricting the angle of inclination to the area necessary and sufficient for forming the inclination angle, it is easier to form the inclination angle with a thinner thickness.

(10) Between the magnet plate MAG and shield case 8HI,
Inclined plate IN such as soft ferrite with large magnetic permeability μ
Since M 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) Since the shield case SHI is made of a magnetic material such as permalloy with a large magnetic permeability μ, the magnetic plate MAG
Since the magnetic resistance of the magnetic circuit using the magnetic field source 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 Bs, it has the function of bypassing external magnetic field noise and preventing it from being transmitted to the chip 1.

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

(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 assembled therein against external mechanical forces.

(15) Since the magnetic circuit PFC for generating a rotating magnetic field and the bias coil BIC are both made of core material, case RF8
, storage efficiency or packaging density within the SHI or PKG can be increased.

(16) Since a case FS is inserted between the core COR and the magnetic shunt plate HOM, the interval between them 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. can.

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 island from the magnet plate MAG will leak into the core COR having high magnetic permeability, and the uniformity of the bias magnetic field in the chip peripheral portion 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 manufactured under the same manufacturing conditions so that there is a rotation angle difference of 180° between the top and bottom surfaces of the chip. A pair of magnetic shunt plates HOM and a pair of magnets M are arranged.
AG can be aligned almost parallel.

(Overview of assembly Fig. 5) Fig. 5 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, there is a board assembly B in which two chips CHI are mounted on a board FPC that has input/output wiring connection parts protruding from the four corners and a chip mounting part in the center.
After placing the ND in an outer case RFSa with an insulating sheet 56 adhesively arranged on the bottom surface and incorporating a magnetic circuit PFC on this board FPC, silicone resin SIR (
(not shown), and the inner case box FSb is assembled into the outer case RFSa on the top thereof, and the outer case RFS
The side contact portions of a and the inner case Feb are electrically connected by soldering or the like.

Next, these outer case RF8a and inner case RF
After arranging the upper magnet body BIMa and the lower magnet body BIMb in the concave constriction provided on the outer surface of Sb, the illustration formed by the outer edge of the upper magnet body BIMa, the inner case R, and the inside of FSb Bias coils wound in an aligned manner are arranged in the gaps between the two sides, and these are housed in the outer shield case 5HIa, and then the inner shield case 5H is placed.
Ib is incorporated, and the side contact portions of the outer shield case 5HIa and the inner shield case 5HIb are magnetically connected by welding or the like.

Next, the external connection terminal connection portions of the board FPC protruding from the four corners of the shield case 8HI are folded back to the back of the inner shield case 5HIb as shown in FIG. 4B, and arranged in a fixed shape. , A terminal fixing plate TEF with a contact pad CNP mounted in each opening is placed in contact with each external connection terminal covered with solder etc. provided at each of these connection parts, and each external connection terminal is attached by thermocompression bonding or the like. It is electrically connected to the contact pad GNP'i by soldering or the like.

Next, these assemblies are stored in the packaging case PKG, and the terminal fixing plate TEF and the packaging case PK
A hermetic seal or other seal is applied to the contact area of G. [Assembled]

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

(7 lexiple wiring board Fig. 4) Fig. 4 shows the board FPC-i. Fig. 4 A is a plan view thereof, and Fig. 4 B is a combination of the external connection terminals protruding from the four corners by folding them together. The plan view of the arrangement, the same figure C is an enlarged cross-sectional view of aC-4c of the same figure A, the same figure is the 40th person of the same figure.
-40 is an enlarged sectional view. In the figure, the board FPC has a rectangular chip mounting part 1 in the center and small bent parts 2 (2a, 2b, 2C, 2) in the four corners.
d) and a square external connection terminal connection part (
(hereinafter referred to as connection part) s (sa, sb, 5c, sd
), and is integrally formed with an almost windmill-like overall shape, and two chips CHI, which will be described later, are mounted on opposite sides of this chip mounting part 1, and their terminal parts are mounted on opposite sides of the chip mounting part 1. A rectangular opening 4 (4a, 4b) with a double frame structure for connection and five perforations 5 (5a, 5b, 5c) for positioning are provided, and a positioning hole is provided at the tip of one connecting portion 3C. A substrate protrusion 6 is provided.

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 the figure are formed.
Patterns such as a circular external terminal 9b, an elliptical coil lead connection terminal 9c, a symbol 9d, and an index mark 9e are formed on the upper surface of these through an adhesive 8 made of the same material as described above. A semi-transparent 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 at ℃.

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.? A solder layer 15 is formed on the CC 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 4a provided in the chip mounting part 1.
.

Each connection part 5a #5b, 5 is attached to a part of the open end of 4b.
The tips of blocks C and 5d are assembled into openings 4a.

4b is exposed. That is, as shown in the figure, the wiring lead 9a of the connecting part 5a is located at the upper left of the opening 4a, the wiring lead 9a of the connecting part 5b is located at the lower left of the opening 4b, and the wiring lead 9a of the connecting part 5C 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 5d is located in the opening 4b.
are wired at the bottom right of each.

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 15.

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

In such a configuration, the substrate FPC is made of a polyimide resin film, and has connection parts 5a, 5b, 5C, and 5d provided at the four corners of the chip mounting part 1 via respective bending parts 2b, 2G, and 2d. These connecting portions 5a, 5b, 5c,
5d is folded back and combined to form the external terminal section, the chip mounting section 1 and the connection section form a two-layer wiring structure, so the area of the chip mounting section 1 can be increased without reducing the area of the connection section 50. In addition, the external terminal portion can be multi-terminal, and the overall shape can be made smaller.

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

That is, signals with a high S/N ratio can be input and output. In addition, a board protrusion 6 is provided at one end of the connecting portion 5C, and an index mark 9e is provided on this protrusion 6, so that the case box FS and SHI can be used to display the central part of the board when folded back and assembled. (Reference)), for distinguishing the type of wiring lead 9a, or for displaying the product model, etc., making it easy to identify, so assembly, board management, etc. can be streamlined. . In addition, the chip mounting part 1 of the board FPC
0 Perforations 5a and 5b on both ends.

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 Figures 5e6e7) Figure 5 shows a plan view of the chip CHI mounted on the FPC board described above. In the same figure, the board FPC
There are two chips CHI in the chip mounting part 1 of the opening 4a.
, board assembly BND mounted in parallel between ab and
As shown in the enlarged plan view in FIG. 6, one chip CHI is constructed by integrating two blocks of IMb, and the two chips CHI have 4 blocks, making a total of 4 Mb chips. It consists of In one block of the chip process shown in FIG. 6, thick lines indicate conductor paroons and thin lines indicate chevron pattern transfer paths. In addition, the chip CHI shown in FIG. 5 is
As shown in the enlarged cross-sectional views of FIG. 7B, the chip C
A gold bump 15 is interposed between each bonding pad 14 provided by gold plating on the end of the HI and the wiring lead 9a on which the tin plating layer 11 of the substrate FPC opening 4 is formed, and the thermocompression bonding is performed. It is mounted by lead bonding using Au-8n eutectic.

According to such a configuration, the opening 4a of the substrate FPC,
The wiring lead 9a of 4b 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. 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 the nearest connecting portions 5g and 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, there are four connection parts 5a and 5b on the FPC board.

5c and 5d, the wires for the magnetic bubble detector DEF and the pine group of each chip CHI are distinguished from other functional wires 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.

(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 consists of four sets of coils k 20a and 20b wound in the direction of the arrows on mutually parallel opposing sides of a frame-shaped core COR made of a soft magnetic material.
, 20c, and 20d are wound. Coils 20a 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 connected to form an injection a. The Y:F coils 22b are formed by winding the coils in series through the Y:F coils 22b. Then, the X coil 22a and the Y coil 22b have a phase of 9.
In addition to supplying currents Ix and Iy (for example, triangular wave currents) that differ by 0 degrees, a leakage magnetic field Hx is generated in the llCx axis direction and a leakage magnetic field HY is generated in the y-axis direction, as shown by BVc in the same figure, and the two aforementioned It is supplied to the chip CHI as a rotating magnetic field.

In addition, the magnetic circuit PFC configured in this manner has windings arranged around a rectangular parallelepiped magnetic core 25 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 a and 20b, a wide groove 25 having a constant width and a narrower groove 26 are formed by cutting between each fill 2Da and 20b.

Thereafter, the wide grooves 25 that are cut from the narrow groove 26 are assembled and glued together in directions orthogonal to each other to form a picture frame shape as shown in FIG. Conversely, the coil 20a is attached to the rectangular parallelepiped core 25 in which the wide groove 25 and the narrow groove 26 described above are formed in advance.
, 20b may be wound through the tap 24 to form a pair of X coils 22a. In addition, the pair of Y
The coil 22b is 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. 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 Figures 10, 11, and 12) Figure 10 is a diagram showing the inner case FSb, in which Figure A is a plan view and Figure B is a 1oB-toB sectional view thereof.

In the figure, the inner case Feb has a frame-shaped constriction part 50 whose central part is concave, a bent part 51 whose opposite end is bent upward by approximately 90 degrees, and each of the four corners of which is diagonally bent. The case RF8b is formed by pressing a highly conductive material such as an oxygen-free copper plate. In this case, the constricted portion 50 and the bent portion 51 can improve the mechanical strength of the inner case RF8b in the torsional direction, and can appropriately limit the outer diameter dimensions in the longitudinal and lateral directions between the bent portions 51 facing each other. . Furthermore, the aperture section 50 can appropriately adjust the distance between the magnet body BIMb disposed on the outer surface side of the case RFSb and the chip CHI disposed on the inner surface side. Note that the notches S2 provided at the four corners are
Each bent part 2a of the board FPC arranged in b,
2b.

It forms the drawer parts of 2C and 2d.

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

Note that although oxygen-free copper is used for the inner case box F8b, a plate material made of copper, silver, gold plate, or a plated alloy plate of these may also be used.

FIG. 11 is a diagram showing an outer case RFSa corresponding to the inner case RFSb described above, in which FIG. 11A is a plan view and FIG. 11B is a 11B-11B sectional view thereof.

In the figure, the outer case RFSa is formed using the same materials and manufacturing method as the inner case Feb described above, and its structure includes a frame-shaped constriction part 55 with a concave center part, almost the same as the above-described structure. A bent portion 34 whose opposite end side is bent upward at approximately 90 degrees, and each of the bent portions 34
The corner has a notch 55 cut diagonally. In this case, the bent portions 3 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 the FSb, and to have a larger height H. Note that the constricted portion 35 and the cutout portion 55 are formed to have substantially the same dimensions as the aforementioned inner case box Feb.

FIG. 12A is a plan view of the outer case RFSa and the inner cases R and F8b configured in this way.

As shown in the 12B-12B sectional view in FIG. 12B, the inner case RFSb is inserted into the outer case RFaa, and the outer surfaces of the bent portions 31 of the outer case RFSa are brought into contact with each other and connected. The case RF8 is assembled.

(Case assembly Fig. 15) Fig. 15 shows the board assembly EN in the case 'RFS mentioned above.
It shows a cross-sectional view of D being housed and arranged.

In the figure, a polyimide film 56 with a thickness of about α1 m, for example, is adhesively arranged as an electrically insulating sheet on the bottom surface of the outer case RF8a.
A board assembly BND is arranged on the top, a magnetic circuit PFC is arranged on the periphery of the board assembly BND, and a board assembly EN is arranged on the top.
After applying an epoxy adhesive 57 to the upper surface of D, an inner case RFSb is inserted into the upper part of these and arranged to be joined. In this case, the inner surface of the bent portion 54 of the outer case RFSa and the outer surface of the bent portion 51 of the inner case RF'Sb are electrically and mechanically joined by metal 7E2- or soldering at the portion indicated by the x mark. There is.

Further, a gap between the outer case RF8a and the inner case RFSb is filled with silicone resin 8IR, and the board assembly BND and the magnetic circuit PFC are fixedly arranged. In this case, each notch 52 and 55 (not shown) provided at the four corners of the outer case RF8a and the inner case RFSb has a bent portion 2 (2a) of the board FPC.

zb-2C#2d) is drawn out. 5
B is a lead wire for connecting the coil COIs or connecting the coil COI to 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 RFS, so that the chip CHI is applied with a uniform rotating magnetic field.

According to such a configuration, the board F is placed in the concave portion at the center between the outer case RFSa and the inner case RFSb.
Since the chip CHI mounted on the PC is arranged with the magnetic circuit PFC sandwiched within the convex portion of the peripheral portion, the packaging effect can be improved and the ease of assembly can be greatly improved. In addition, by reducing the volume covered by the outer case RFSa and the inner case gpsb, V
The I product (OC volume) can be reduced, and the magnetic circuit PFC that generates the rotating magnetic field can be downsized. Further, there are throttle portions 50, 5 in the outer case RFSa and the inner case RFSb.
By reducing the gap between the opposing concave portions, the rotating magnetic field has a component (two components) perpendicular to the plane of the chip CHI that approaches zero and becomes only a horizontal component. - You can improve your guts @Also,
The magnetic circuit PF is aligned with the axis perpendicular to the element surface of the chip CHI.
Since C and case RFS have nearly symmetrical structures, uniform injection can be further 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, a magnet plate HOM with a uniform plate thickness arranged on the inclined surface side of this inclined plate I, a magnet plate MAG with a uniform plate thickness arranged on the upper surface side of this magnet plate HOM, and this magnet plate. An inclined plate INM having an inclined surface on the upper surface side of the MAG is sequentially layered and integrated with an epoxy adhesive, so that the overall laminated plate thickness is uniform over almost the entire surface. . A uniform 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 a bias coil BIC, and FIG. 15A is a perspective view, and FIG. 1B is a 15B-15B sectional view thereof. 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
Since it is cured in a bundled state, it is 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 BIC described above inside the case RFS assembly explained in Figure 13.
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 B is placed in a frame-shaped groove surrounded by the peripheral edge of the inner case R and the bent portion 51 of the inner case R and FSb.
IC is stored and arranged.

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

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 几FSa
A frame-shaped space groove is formed between the outer edge portion of the lower magnet body BIMb, and the bias coil BI is inserted into this portion.
C may be arranged, or 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 case Figs. 17, 18, 19) Fig. 17 is a diagram showing the outer shield case 5HIa,
Figure A is a plan view, and Figure B is a cross-sectional view taken along line 17B-17B. In the figure, the outer shield case 8HIa is
A flat part 51, a bent part 52 which is folded upward at an angle of approximately 90 degrees on the opposite end of the flat part 51, a recessed part 55 which is partially cut out in the center of this bent part 52, and each of the four parts. The outer shield case 5HIa is made of a material having high magnetic permeability and high saturation magnetic flux density, and preferably high thermal conductivity, such as permalloy. It is formed by pressing a plate.

FIG. 18 is a diagram showing an inner shield case 8HIb corresponding to the above-mentioned outer shield case 8HIa, and FIG. 18 is a plan view, and FIG. 18B is a cross-sectional view taken along line 18B-taB. In the figure, this inner shield case 5HIb is formed using the same materials and manufacturing method as the above-mentioned outer shield case 8HIa, and its structure is almost the same as that described above, with a flat part 55 and an opposite edge of this flat part 55. A bent portion 56 that is folded upward at approximately 90 degrees, a recessed portion 57 that is partially cut out in the center of this bent portion 56, and notched portions 58 that are cut diagonally at each of its four corners. It is configured with 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 5HIa described above, and have a small height H. It is formed.

The outer shield case 5HIa and the inner shield case 8HIb configured in this way are shown in a plan view in FIG. 19A and in a sectional view taken along line 19B-19B in FIG. The inner shield case 5HIb is inserted into the inner shield case 5HIb, and the recess 59 formed by the recess 55 of the outer shield case 5HIa and the recess 57 of the inner shield case SHIb is spot welded or soldered to fix it magnetically and mechanically. The shield case 8HI is assembled by integrating the shield case 8HI.

In such a configuration, the outer shield case 5HIa
By setting the bent portion 52 of the inner shield case 8HIb and the bent portion 56 of the inner shield case 8HIb in the lateral direction, that is, in the direction that intersects with the laminating direction, by aligning them with the laminating direction, the lateral dimension can be reduced, making it compact. In addition, high integration of component parts becomes possible.

(Magnetic shield case assembly Fig. 20) Fig. 20 shows a board assembly BND and a magnetic circuit PFC inside the above-mentioned shield case 8HI assembly as explained in Fig. 16 above.
A case RFS assembly incorporating the BI
A cross-sectional view incorporating an assembly consisting of Ma, BIMb, and bias coil BIC is shown. In the figure, the inside of the outer shield case 8HIa includes an upper magnet body BIMa in the center from the bottom side, a bias coil BIC in the periphery, and a case RFS assembly (board assembly END, magnetic circuit PFC, etc. are incorporated inside). After sequentially stacking and arranging the lower magnet bodies BIMb, the inner shield case 81 (Ib) is inserted, and the recess 55 of the outer shield case SHIa and the recess 57 of the inner shield case 5HIb described above are formed. recess 59 (19th
(see figure) is welded and sealed. In this case, the shield case SHI is filled with grease or the like (thereby, the internal components are substantially brought into close contact with each other, and the heat generated from the case RFS is transferred through the shield case SHI). Can be released to the outside.

Furthermore, the heat dissipation effect can be improved by making the case RFS and the shield case 8HI contact each other at their sides by press-fitting.

In such a configuration, the outer shield case 5HIa
Place the case FS 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 8H.
Since each component laminated between Ib and Ib 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) FIG. 21 is a diagram showing a packaging case PKG, in which FIG. 21A is a plan view and FIG. 21B is a 21B-21B sectional view thereof. In the figure, the packaging case PKG is formed by drawing a material with good thermal conductivity, for example, an aluminum plate with a thickness of 0.54 mm, and has a black coating on its outer surface (not shown). ing. This packaging case PKG is the outer shield case 8H.
It is possible to improve the shape of Ia and use it for both purposes.

In such a component, 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 Figures 22 and 25) Figure 22 is a diagram showing the terminal fixing plate TEF, where A is a plan view, B is a cross-sectional view 22B-22B, and C is a cross-sectional view of 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, for example, a glass epoxy resin plate 60, and its outer shape has dimensions in the vertical and horizontal directions that allow it to be inserted and inserted into the opening of the packaging case PKG. In addition, a large number of through holes 61 are formed in a matrix arrangement at predetermined intervals in the vertical and horizontal directions in the resin plate 60 except for the periphery, and the corners of these through holes are A non-through hole 62 having a concave cross section that is not rotationally symmetrical is provided in the non-through hole 62, and a mark 65 made of, for example, a white coating film for locating the directionality or feature is attached to the inside of the non-through hole 62. In addition, as shown in FIG. B, a large number of through holes 61 formed 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 FIG. All of the openings 64 have a depth of about 60% of the plate thickness, and communicate with the through hole 61 with a step in the middle. Further, as shown in FIG. C, the back side of the 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 C is placed inside this groove 65.
It constitutes a passage section and a connection section for the winding of the OI 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 back side of the resin plate 60 is formed to have a two-stage structure with different plate thicknesses.

FIG. 25 is a diagram showing the contact pad GNP, in which FIG. 25 is a plan view and FIG. 25B is a sectional view thereof. In the figure, the contact pad GNP is formed by forming a nickel plating layer 71 on the surface of a blank piece 7o punched out of a highly conductive material, for example, a copper plate with a thickness of about 0.5 m, by press working. It is constructed by forming a gold plating layer 72.

(Final Assembly FIG. 20.4.2) For each component configured in this way, first insert the shield case assembly described in FIG. 20 into the packaging case PKG described above. In this state, each connection part 5a, 5b, 5c, 5 of the board assembly BND is connected from the four corners of this packaging case PKG.
d (see Fig. 4A) is the bending portion 2a, 2b.
, 2c, and 2d, bending at about 90 degrees and protruding. Next, resin molding is performed at the four corners of this packaging case PKG by a botting method, and each individual component is fixedly arranged inside this packaging case PKG. Subsequently, each of these connection parts 5a, 5b, 5c
, 5d to 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 the terminal fixing plate T
A packaging case PKG K is created by mounting a contact pad CNP in each opening 64 on the back side of the EF, or by further fixing the side surface of the contact pad GNP with adhesive.
Insert each connection part 5a, 5b, 5c, 5d
Place it in contact with the In this case, each connection part 5a, 5b
, 5c, and each external terminal 9b provided on 5d.
Since the arrangement pitch of and the arrangement pitch of each contact pad CNP match, each external terminal 9b and contact pad GNP are in electrical contact with each other. 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 thermocompressing the contact pad GNP, each contact pad GNP corresponding to each external terminal 9b is electrically connected. Terminal fixing plate T
EF is also mechanically fixed at the same time to complete 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 (gado l ini Am
-gallium-garnet) is a substrate, LPE is a bubble magnetic film formed by a liquid phase epitaxial growth method, and an example of its composition is as shown in Table 1 below.

ION indicates an ion implantation layer formed on the surface of the KLPB film to suppress hard bubbles. 8P 1 is the first spacer 1, for example 8i0 with a thickness of 5000 A'
2 is formed by a gas phase chemical reaction. CON 1 and C
ON 2 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 CON 1 is Mo, and the upper second conductor layer The conductor layers CON 2 are each made of a material such as Au. 8P 2 and 8P s are glabella insulating films (second
, fifth spacer). PAS is a badge film made of 8i02 film or the like produced by the vapor phase chemical reaction department. PAD indicates a bonding pad of the chip CHI, and a thin connector wire such as a company 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 the Au layer, and the fifth layer PAD above
The second layer PAD 2 and the fifth layer PAD s 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 1 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 is used for the upper layer P2 and Fe-Ni is used for the upper layer P2, 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. 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. 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.

BR is a bubble eraser, and when a bubble reaches the conductor layer CND, it is erased. A guardrail ()R consisting of a group of five patterns is provided around this detector and between the dummy and main detection, and the guardrail G
They are busy expelling unnecessary bubbles generated inside the guardrail GR to the outside, and preventing unnecessary bubbles generated outside the guardrail GR 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 figure, magnetoresistive element ■M.

By forming the MED with multilayer magnetic layers, the signal-to-noise ratio (87N ratio) was improved. For example, if an S-layer permalloy layer with an 8i02 film interposed between each layer is used as a transfer pattern, the SZN ratio can be improved by more than twice compared to a single-layer permalloy layer, as shown in Table 2 below. .

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

FIG. 26 shows the magnetic bubble generator GEN, and by making the transfer pattern layer P multilayered, the current generated by magnetic bubbles can be reduced.

It has become possible to extend the life of the conductor layer CHD of the magnetic bubble generator. Therefore, a fast conductor element with a small current capacity value can be used in the drive circuit for the conductor N CND, and the cost can be reduced.

FIG. 27 shows a minor loop fn formed by a transfer pattern such as PaxPh, a write major line WML formed by a transfer pattern sequence such as P%v1 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 K in FIG. WMLK transfer. When a current is passed through the swap conductor layer CND, the transfer pattern P of the minor loop m1
The magnetic bubble of d is transferred to the transfer pattern Pw 5 ic of the major line WML through the transfer patterns PL and Pm, and the magnetic bubble from the major line Pw 1 is transferred to the transfer pattern Pei of the minor loose via the transfer patterns Pk, Pj, and Pi. Then, bubbles are exchanged, that is, information is rewritten. Note that the rightmost minor loop ml is not provided with a swap gate, but this is a dummy loop in which no magnetic puzzle is injected to reduce the peripheral effect. By multilayering the transfer pattern layer PixPm at the exchange position in this manner, 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-Py, Ps
The bubble is transferred along the normal path P-Px, and when a current is applied to the conductor layer CND, the bubble is divided at the position of the transfer pattern P), and one divided magnetic bubble is Py, P8 to P1.
Read major line RML <transferred via 0.

(Holding magnetic field and rotating magnetic field Fig. 29) Magnet plate MAG is placed at an angle of about 2 degrees with respect to chip CHI. This is done so that the bias magnetic field island is applied to the chip CHI with a slight deviation from the perpendicular direction.
This creates a holding magnetic field Hdc that improves the start and stop margins of bubble transfer by about 6 rOe (Figure 29).

As shown in Figure 29, magnet body BIM and chip CHI
Due to the inclination of the angle θ 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 θ is selected so that c −s in θ=s C0e) ~ 6 (Oe). Also, the direction of this in-plane component Hdc is the start/stop (8t/8p) direction of the rotating magnetic field Hr ( + This is a well-known magnetic field that acts on the chip CHI surface.The magnitude of the bias magnetic field Hb that acts perpendicular to the chip CHI surface is Hz・(o
It becomes sθ.

Now, since the above-mentioned holding field Hdc always acts on the chip CHIOxy surface, the 29th
As illustrated in Figure BK, 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 acting on the chip CHI. 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 the start/stop (St/8p
) direction, which is the +X-axis 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 1 Hrl, 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, l Hr' l in the at/8p direction is 1Hrl+1H
dcl, which is stronger than 1Hrl by the strength of the holding field Hdc l Hd e l. Conversely, lHr'l in the opposite direction to the St/Sp direction becomes 1Hrl -IHdcl, and 1Hrl is 1H in comparison.
Only dcl is weakened.

(Peripheral circuit Fig. 50) Finally, the peripheral circuit of chip CHI will be explained with reference to FIG.

R and F are circuits for flowing currents with a phase difference between the X and Y coils Vc90 of the chip CHI to generate a rotating magnetic field Hr. 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. DB is
This 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 synchronized by the timing generation circuit TGK so that it operates in synchronization with the cycle and phase angle of the rotating magnetic field Hr.

(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 center 0 in the magnetic circuit PFC shown in FIG.
When the single rotational magnetic field strength in the X-axis direction is shown when it is set to 0, a rotating magnetic field distribution characteristic as shown by curve I was obtained. As is clear from the figure, an almost uniform strong rotating magnetic field can be produced within the range of -Xc to +Xc between the opposing cores COR of the magnetic circuit PFC, and the chip C
Effective area of HI (minimum range to which rotating magnetic field should be applied)
In the range of -Xe to 10Xe, a magnetic field strength of ±2% was obtained. Incidentally, the curved line indicated by the broken line is the rotating magnetic field distribution characteristic due to the magnetic circuit of the conventional configuration.

〔Effect of the invention〕

As explained above, according to the present invention, the magnetic bubble memory chip mounted on the 7-lexiple wiring board is disposed in the space of the rotating magnetic circuit of the frame-shaped core, and the whole is placed in the rotating magnetic field of the highly conductive material. By sandwiching it inside the confinement case and electrically connecting its peripheral edge, 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, and the rotating magnetic field confinement case can be made smaller. By being able to reduce power consumption,
Moreover, an extremely excellent effect can be obtained in that a magnetic bubble memory device whose overall shape is made smaller and thinner and whose assemblability is improved 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. 2A is a bottom view, Fig. 2B is a sectional view taken along line 2B-2B of Fig. 5A, 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 E with chip CHI mounted on the board FPC.
FIG. 6 is a plan view showing the chip CHI, FIG. 7 is a diagram explaining lead bonding of the board assembly BND, FIG. 8 is a diagram explaining the magnetic circuit PFC, and FIG. 9 is a diagram showing the magnetic circuit. A diagram explaining the manufacturing method of PFC, FIG. 10 is a diagram showing the inner case RFSb, and FIG. 11 is a diagram showing the outer case RF.
8a, Figure 12 is an assembly diagram of case RF8, 1st
3 is a sectional view of an assembly in which the board assembly BND and the magnetic circuit PFC are housed in the case RFa, FIG. 14 is a diagram illustrating the configuration of the magnet body BIM, and FIG. 15 is a diagram illustrating the bias coil BIC. FIG. 16 is a cross-sectional view of a case RF8 assembly incorporating a pair of magnets BIM and bias coil BIC, FIG. 17 is a diagram showing the outer shield case 5HIa, and FIG. 18 is a diagram showing the inner 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 TBF, FIG. 25 is a diagram showing the structure of the contact pad CNP, 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. Figure 26 shows the configuration of the magnetic bubble generator GEN of chip C) (Figure 27 shows the configuration of the magnetic bubble generator GEN of chip CH)
FIG. 28 is a diagram showing the configuration of the replicate gate arm P of the chip CHI, FIG. 29A is a diagram showing the relationship between the bias magnetic field Hb and the holding magnetic field Hdc, and FIG. is the total rotating magnetic field Hr
50 is a diagram showing the entire circuit of the magnetic bubble memory board, and FIG. 51 is a diagram showing the rotating magnetic field distribution characteristics. CHI's magnetic bubble memory chip (chip), FPC
s Flexible wiring board (board), BND s Substrate assembly, COI s Drive coil (coil), CO91 picture frame core (:1A), PFCs magnetic circuit, RPS s Rotating magnetic field confinement case (case), RF8
a s outer case, RF8b inner case, BIM s bias magnetic field generation magnet (magnet), B
IMa s upper magnet body, BIMb sT section magnet body, INM s inclined plate, MAG s permanent magnet plate (magnetic plate), HOM s magnetic shunt plate, INN i non-magnetic inclined plate, BICs bias magnetic field generation coil (bias coil) , 8HIs external magnetic shield case (shield case)
, 8HIas outer shield case, 8HIbs inner shield case, PKGs packaging case, TBFs terminal fixing plate, CNP, contact pad, 1s chip mounting part, 2.2m, 2b, 2C, 2d l bending part, 5, 5
a, 5b, 5c, 5d s External connection terminal connection section, 4.4
a, 4b, opening, 5.5a, 5b, 5c; perforation/61 board protrusion, 71 base film, 8a adhesive, 9a S wiring lead, 9b s external terminal, 9c s connection terminal, 9d s symbol , 9e s index mark, 10s cover film, 11s tin plating layer, 12a opening, 15s solder plating layer, 14s bonding pad, 15s gold bump, 20a, 20b, 20c, 20d s coil, 21a,
21b s connection point, 22 as part, 541 bent part, 55 i notch part, 56 s polyimide film, 571 adhesive, 58 coil winding, 401 winding, 51% flat part, 52 s bent part, 55 l concave part, 54 small notch part , 55 s flat part, 56 B cut and bent part, 57 s recessed part, 58 s notch part, 591 recessed part, 60 rich resin board, 61 through hole, 621 non-through hole, 65 small mark, 64 s opening, 65 grave groove, 66 s corner, 70 s piece, 71 s nickel plating layer, Fig. 4 C Fig. 4 Fig. 5 Fig. 6 IY Fig. 8 B HT 5α Fig. 12 A Fig. 12 B Fig. 14 A Figure 14B Figure 14C ) (OX INNNN 1st mu Figure 17A Figure 18A Figure 18B Figure 19A Figure A Figure 22B +llL ζtko<LL (L(1) Figure 26Figure 28

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 rotating magnetic field confinement case, the magnetic bubble memory chip mounted on the wiring board, and the wound core are assembled by stacking them in a uniaxial direction.