JPS61248287A - Magnetic bubble memory device - Google Patents

Abstract

PURPOSE:To utilize a flexible wired board for mounting a chip effectively by forming the flexible wired board having a chip mounting part and an externally connecting terminal connection part almost rectangularly. CONSTITUTION:The flexible wired board having the chip mounting part and the externally connected terminal connecting part is formed almost rectangularly. The board FPC is combined so that respective connecting parts 3a-3d are bent at respective bending parts 2a-2d and cover the whole beak of an inner shielding case SHIb. The area of the chip mounting part 1 is made almost equal to that of the connecting part 3 and the center part of the border part is cut out to narrow the width and utilize the cut-out part as bending parts 2 (2a, 2b). In addition, a pair of externally connected terminal connection parts 3a, 3b are formed on both the sides of the chip mounting part 1 and the center part of the border part is cut out to narrow the width and utilizes the cut-out part as bending parts 2 (2a-2d).

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 assembly.

[Background of the invention]

Magnetic bubble memory technology, which has been put into practical use in recent years, generates a rotating magnetic field consisting of a rectangular solenoid coil with an asymmetrical structure on a figure-8-shaped wiring board made of ceramic or synthetic resin on which a magnetic bubble memory chip is mounted. X coil for.

It has a structure in which each X coil is inserted and arranged orthogonally. The X-coil and the X-coil are structured to wrap not only the magnetic bubble memory chip but also a wiring board that is much larger than the chip, so each coil is long from end to end.

Drive voltage and power consumption will increase. In addition, the X coil and Y coil require a uniform inductor balance in order to provide a uniform and stable in-plane rotating magnetic field to the magnetic bubble memory element, so the coil shapes are different from each other and have an asymmetric structure, resulting in a larger structure. I had no choice but to do so. Furthermore, a pair of permanent magnet plates that apply a perpendicular bias magnetic field to the magnetic bubble memory element and a magnetic shunt plate are arranged on the outer surfaces of these X coils and Y coils, and their peripheral parts are covered with a resin mold. Because of this structure, the stacking thickness in the vertical direction increases, which is 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 t.
1! f.

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.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic bubble memory device that is thinner and smaller, and that makes effective use of a flexible wiring board on which a chip is mounted.

[Summary of the invention]

The present invention provides a magnetic bubble memory chip mounted on and electrically connected to a chip mounting portion of a flexible wiring board having a chip mounting portion and an external connection terminal connection portion, and winding wires on two sets of two opposing sides. In the magnetic bubble memory device, the magnetic bubble memory chip, the winding, and the core are placed in a position surrounded by a rectangular annular core with The present invention is characterized in that a flexible wiring board having a connection terminal connection portion is formed into a substantially rectangular shape, thereby making effective use of the flexible board and improving handling performance and positioning accuracy during assembly.

[Embodiments of the invention]

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

FIG. 1 and FIGS. 2A and 2B are diagrams for explaining the magnetic bubble memory device targeted by the present invention.
The figure is a partially cutaway perspective view, Figure 2 is a bottom view of the person, Figure 2B
is a sectional view taken along line 2B-2B of FIG. In these figures, CHI is a magnetic bubble memory chip (hereinafter referred to as chip), and in these figures only one chip CHI is omitted, but in this example two chips are arranged side by side. do. (The chip yield is better with a multi-divided chip configuration that matches the zero total memory capacity than with one large-capacity chip.) The FPC is equipped with two chips CHI, and has chip CHI and external connection terminals at the four corners. This is a flexible wiring board (hereinafter referred to as the board) having a wire group long section for connection to the board.

The COI surrounds the two chips CHI on substantially the same plane, and is a drive coil (hereinafter referred to as a coil) arranged so that opposing sides are parallel to each other.

In the i@3 diagram, the symbols 20a, 20b, 2
0c and 20d are attached. ), COR is a frame-shaped core (hereinafter referred to as core) made of soft magnetic material fixedly arranged so as to penetrate the hollow part of the square coil assembly COI, and this core COR and each coil COI form a chip CHI. Magnetic circuit PFC that provides an in-plane rotating magnetic field
I am trying to configure it.

The RFS is a rotating magnetic field confinement case (hereinafter referred to as the case) that houses the central rectangular portion of the substrate FPC, two chips CHI, and the entire magnetic circuit PFC. The case RFS is formed by processing two independent plates, and the upper and lower plates are electrically connected at the side surface of the case. These cases RFS have constricted portions (30, 33 in FIG. 3) formed in the peripheral portions so that the gap in the central portion is narrowed in a slightly wider range than the portion where the chip CHI is arranged. This constriction portion can also be used for positioning the magnet body, which will be described later. The case RFS has the effect of confining the rotating magnetic field and mechanically supporting the soft substrate jPC, killing two birds with one stone.

In particular, there is a chip C between the case RFS and the chip CHI.
There is a gap SIR on the side of HI.

This gap SIR, including the flat surface of the chip CHI, is coated or filled with silicone resin to prevent foreign matter from adhering to the main surface of the chip during assembly or moisture from entering the main surface or side surfaces of the chip after assembly. so that it becomes less
A pudge effect is intended. If a complete airtight seal is possible outside the case RFS, the resin SI
Filling with R 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 RFS side. As a material for inclined plate INM.

Soft ferrite or permalloy, which has a high magnetic permeability μ and a low coercive force Hc, may be used, and in this example, soft ferrite was selected because it is easy to process an inclined surface. MAG is a pair of permanent magnet plates (hereinafter referred to as magnet plates) arranged inside a pair of inclined plates INM and overlapped with them.ROM is a soft ferrite magnet arranged inside each magnet plate MAG and overlapped with it. These are a pair of magnetic shunt plates made of magnetic material.The magnet plate MAG is formed to have a uniform plate thickness over the entire surface.The INN is placed on the inner facing surface of the pair of magnetic shunt plates HOM, overlapping with it. These are a pair of inclined plates made of a non-magnetic material with good thermal conductivity, such as copper. Slanted plate IN
M, magnet plate MAG, magnetic shunt plate HOM, and inclined plate INN are:
When stacked and arranged to form a bias magnetic field generating magnet body BIM (hereinafter referred to as magnet body), the thickness of the entire laminated plate magnet body is formed to be uniform over almost the entire surface. ing. A pair of magnets BI
M is glued to the 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 filter BIC is driven to adjust the magnetic force of the magnet plate MAG to match the characteristics of the chip CHI, to test for the presence or absence of unnecessary bubble generation defects, and to clear all bubbles of the chip CHI. .

SHI is a case RFS that houses a substrate FPC on which the chip CHI is mounted and a magnetic circuit PFC, and a pair of magnets BIMa outside the case RFS.

This is an external magnetic shield case (hereinafter referred to as shield case) made of a magnetic material that houses BIMb and bias coil BIC. The material for the shield case SHI has a high magnetic permeability μ.

A magnetic material with a large saturation magnetic flux density Bs (and a small Hc) is preferable, such as permalloy or ferrite, which has such characteristics. An iron-nickel alloy was selected.

PKG is a packaging case made of a material such as υ, which has high thermal conductivity and is easy to process, and is attached to the outer peripheral surface of the shield case SHI by adhesion or fitting. 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 CNP at the stepped portion of the opening. REG is a molding agent that is sealed in the four inner corners of the packaging case PKG and fixes the shield case SHI assembly inside the packaging case PKG.

FIG. 3 is an assembly perspective view for explaining the procedure for stacking and assembling each component constituting the above-described magnetic bubble memory device, and the same reference numerals as above indicate the same members. In the same figure, first, a board assembly BND in which two chips CHI are mounted on a board FPC which has connection parts 3 for input/output wiring protruding from the four corners and has a chip mounting part 1 in the center is placed on the bottom surface. It is placed inside an outer case RFSa to which an insulating sheet 36 is adhered.

Furthermore, after incorporating the magnetic circuit PFC on this board FPC, silicone resin 5IR (not shown) is filled, and the inner case RFSb is assembled on top of the silicone resin 5IR to the outer case RFSa, and the outer case RFSa and the inner case RFS
The side contact portion with b is electrically connected by soldering or the like.

Next, these inner case RFSb and outer case RF
After arranging the upper magnet body DIMa and the lower magnet body I3IMb in the concave constriction portion 30.33 provided on the outer surface of Sa, the outer edge of this upper magnet body B I Ma and the inside of the inner case RFSb are connected. A bias coil BIC wound in an aligned manner is arranged in a gap (not shown) formed by the above, and these are housed in the outer shield case SHI a, and the inner shield case 5HIb is further incorporated, and the outer shield case SHI a and the inner shield case 5HIb are Connect the side surface contact part magnetically by welding, etc.

Next, from the four corners of the shield case SHI to the outer case RFS
Notch part 35 of a. The external connection terminal connection part 3 of the board FPC protruding through the cutout part 54 of the outer shield case SHIa is connected to the back surface of the inner shield case 5) through the cutout part 58 of the inner shield case TIb with the bent part 2 attached to the first As shown in the figure, the contact pads CNP are folded back to cover the entire back surface from the inner shield case SH and arranged in combination, and each external connection terminal 9b provided in each of these connection parts 3 and covered with solder etc. is connected to a contact pad CNP. A terminal fixing plate TEF mounted in each opening is placed in contact with each external connection terminal 9b and contact pad CN by thermocompression bonding or the like.
Connect P electrically 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 are
The contact portion of G is sealed with a metal seal or the like and then assembled.

A partially cutaway perspective view of the device thus assembled is shown in FIG. 1, and a cross-sectional view is shown in FIG. 2BK.

Figure 4 is a diagram showing the board FPC, Figure A is a plan view thereof, Figure B is a plan view in which the connection parts of the external connection terminals protruding from the four corners are folded back and assembled, and Figure C is the same figure. 4O-4C enlarged sectional view of Figure A, the same figure is 4D-
It is a 4D enlarged sectional view. In the figure, the board FPC is.

A square chip mounting part 1 is provided in the center, and small bent parts 2 (2a, 2b, 2c, 2a, 2b, 2c,
2d), and a square external connection terminal connection part (hereinafter referred to as a connection part) 3 (3a, 3b, 3c, 3
d), and is formed integrally with the overall shape almost like a windmill, and on the opposite side of the chip mounting section 1! As shown in Figure 5, a rectangular opening 4 (4
a, 4b) and three positioning holes 5 (5a, 5
b, 5c), and a substrate protrusion 6 for positioning is provided at the tip of one connecting portion 3c.

Moreover, as shown in FIG. 4CK, this board FPC has a three-layer structure of an insulating layer, a wiring layer, and an insulating layer, and is placed on a base film 7 made of a polyimide resin film having a thickness of about 50 μWL, for example. A copper thin film is formed via an epoxy adhesive 8.

By etching this into a desired pattern shape, a wiring lead 9a, a circular external terminal 9b, an elliptical coil lead connection terminal 9c, as shown in FIG. 4A, are formed.
Patterns such as symbols 9d and index marks 9e are formed, and a transparent or semi-transparent cover film 1o is adhered to the upper surface of these through an adhesive 8 made of the same material as described above.

In the opening 4 of this substrate FPC, an opening is formed in the base film 7 on the chip CHI mounting side with highly accurate dimensions.

A relatively large opening is formed in the upper cover film 10, and a wiring lead 9a is exposed between the base film 7 and the cover film 10, and the surface of the wiring lead 9a is coated with, for example, tin. A plating layer 11 is formed, and the opening has a two-layer structure and a double frame structure.

The chip C) (I is this exposed wiring lead 9
For example, lead bonding is performed on a. On the other hand, in the connection part 3, a cover film 10 is used as shown in the same figure.
A circular opening 12 is formed at a portion corresponding to the circular external terminal 9b and the oval external terminal 9C (not shown), and the external terminals 9b and 9c are exposed from the opening 12.
A solder layer 13 is formed on the copper thin film pattern by plating or dipping. The external terminals 9b and 9c provided in these connecting portions 3 are connected to each connecting portion 3.
a, 3b.

3c, 3d and bent portions 2a, 2b,
2c, 2d and each wiring lead 9aK formed continuously on the chip mounting part 1 are connected, and these wiring leads 9a are connected to each opening 4a provided in the chip mounting part 1.
.

Each connection part 3a, 3b, 3 is attached to a part of the open end of 4b.
c, 3d blocks are gathered together, and the tips thereof form openings 4a.

4b is exposed. That is, as shown in FIG. 4A, the wiring lead 9a of the connecting part 3a is connected to the upper left of the opening 4a, the wiring lead 9a of the connecting part 3b is connected to the lower left VC of the opening 4b, and the wiring lead of the connecting part 3C. 9a is wired to the upper right of the opening 4a, and the wiring lead 9a of the connecting portion 3d is wired to the lower right of the opening 4b.

Then, this board FPC is formed by bending the connecting portions 3a, 3b, 3c, and 3d at the respective bending portions 2a, 2b, 2c, and 2d, and bending them inside as shown in FIG. 3B. The external terminals 9b and 9c are combined so as to cover the entire back surface of the shield case 5HIb, and the solder layer 13 is formed on the external terminals 9b and 9c, and the wiring leads 9a, the symbol 9d, and the index mark 9 are exposed on the surface.
Since the surface of the pattern e is covered with the cover film IOK, these patterns are configured so that they can be easily read through the cover film IO.

In such a configuration, the board FPC uses a polyimide resin film, and has connection parts 3a, 3b, 3c, and 3d provided at the four corners of the chip mounting part 1 via the respective bending parts 2a, 2b, 2c, and 2d. It is structured as follows.

Each of these connection parts 3a, 3b, 3c, 3d
By folding them together to form the external terminal section.

Since the chip mounting part 1 and the connection part have a two-layer wiring structure,
without reducing the area of the connecting part 30.

The area of the chip mounting section 10 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 portion l can be significantly shortened, 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 part 3C, and an index mark 9e is provided on this protrusion 6, so that it can be used for displaying the central part of the board when folded back and assembled. It can be used for positioning when assembling (see Figure 2), for distinguishing the type of wiring lead 9a, or for displaying the product model, etc., making it easy to distinguish, thereby streamlining assembly, board management, etc. I can do it. Additionally, holes 5a and 5b are provided at both ends of the chip mounting portion 10 of the FPC board.

By providing 5c, it becomes easier to distinguish between the left and right sides of the FPC board and to position the chip CHI.

Similarly, assembly efficiency can be streamlined.

FIG. 5 shows a plan view of the chip CHI mounted on the FPC board mentioned above. In the same figure, the board FPC
The chip mounting part IVc has two chips CHI in the opening 4.
The board assembly BN is mounted in parallel between a and 4b.
It consists of D.

One chip CHI is configured by integrating two blocks of 0, IMb, for example, and two chips CHI constitute 4 blocks, making a total of 4 Mb chips.

An object of the present invention is to effectively utilize a flexible substrate, improve the handling of the substrate assembly BND, and improve the positioning of the external connection terminal connector 3 when bending it. That is, since the above-described FPC board has a pinwheel shape, the utilization efficiency of the material is low, and it is not always satisfactory in terms of handling and positioning.

First and second embodiments of the present invention that solve this problem are shown in FIGS. 6 and 7. In the figure, the same reference numerals as those shown in @4 indicate the same components. The basic structure of the present invention is to make the external shape of the FPC board almost rectangular, which reduces waste and effectively utilizes the film that is the material of the FPC board, and also improves handling during device assembly. It is something that improves.

Furthermore, by integrating the external connection terminals.

Handling performance and terminal alignment accuracy can be improved.

In the embodiment shown in FIG. 6, the chip mounting part l and the external connection terminal connection part 3 have approximately the same area, and the central part of the boundary part is cut out to make the width narrower, and this part is bent into parts 2 (2a, 2b). It is used as a. According to this configuration, the film used as the material can be effectively utilized, and since the connecting portion 3 is centrally integrated in one place, handling performance and positioning accuracy during board assembly are greatly improved.

In the embodiment shown in FIG. 7, a pair of external connection terminal connecting portions 3a and 3b are provided on both sides of the chip mounting portion 10, and the central portion of the boundary between these portions is cut out to make the width narrower, and this is the bent portion 2.
(2a, 2b, 2c, 2d). According to this configuration, as in the embodiment shown in FIG. 6, effective use of the film material is achieved, and since the connecting portions 3 are integrated in two places, non-linkability and positioning are achieved when assembling the board. The alignment accuracy is greatly improved.

〔Effect of the invention〕

According to the present invention as described above in detail.

The flexible wiring board on which the magnetic bubble memory chip is mounted can be effectively utilized, and the handling of the board is improved.2 The positioning accuracy is improved, and the ease of assembly is extremely improved.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view showing the entire magnetic bubble memory device in the process leading to the present invention. Fig. 2A is a bottom view, Fig. 2B is a sectional view taken along line 2B-2B of Fig. 2A, Fig. 3 is an exploded perspective view showing the stacked structure, Fig. 4 is a diagram explaining the board FPC, Fig. 5 is FIG. 3 is a plan view showing a board assembly BND on which a board FPCK chip CHI is mounted. 6 and 7 are plan views showing two embodiments of the present invention. FPC...Flexible wiring board. 1...Chip mounting section. 2a, 2b, 2c, 2d = bent portion. 3, 3a, 3b...External connection terminal connection section. 4, 4a, 4b...opening, 9a...wiring lead. 9b...External terminal.

Claims (1)

[Claims] 1. A magnetic bubble memory chip mounted on and electrically connected to a chip mounting portion of a flexible wiring board having a chip mounting portion and an external connection terminal connection portion is attached to two sets of two opposing sides. The above magnetic bubble memory chip is placed in a position surrounded by a rectangular annular core each having a wire wound thereon.
A magnetic bubble memory device in which a winding and a core are covered with a rotating magnetic field confinement case, characterized in that the flexible wiring board having the chip mounting part and the external connection terminal connection part is formed into a substantially rectangular shape. memory device. 2. The magnetic bubble memory device according to claim 1, wherein the chip mounting portion and the external connection terminal connection portion have approximately the same area and are bent at the boundary thereof. 3. A pair of external connection terminal connection parts are provided on both sides of the chip mounting part, and the pair of external connection terminal connection parts are bent at the boundary with the chip mounting part. The magnetic bubble memory device according to item 1.