JPS599100B2 - bubble domain memory device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bubble domain memory device, and more particularly to a simple structure of a large capacity bubble domain device.

Bubble domain memory devices (hereinafter referred to as devices) in the prior art have a capacity of 16kbi per device due to their manufacturing technology.
It was possible to obtain a storage capacity of only about 100,000 yen.

Therefore, in order to obtain a large-capacity bubble domain device, a plurality of elements are arranged in a plane, and two coils whose winding axes are orthogonal to each other are arranged around the outer periphery to obtain a rotating magnetic field. Therefore, a large coil is required to cover a wide area where many elements are arranged with a uniform magnetic field. A rotating magnetic field is obtained by applying an alternating current of about 100 kHz to this coil, but since the coil is large, a transistor that can provide a large output is required, and the withstand voltage of that transistor is also high, which is required for the drive circuit. The conditions were extremely difficult. In addition, in order to shorten the waiting time for reading, it is possible to increase the frequency of the rotating magnetic field, but under conditions that require large output, 300k
It has been very difficult to obtain frequencies of H2 or higher. Furthermore, when a large number of elements are placed in a rotating magnetic field, if the elements are not aligned horizontally and directionally accurately, unnecessary noise may be superimposed on the readout signal and detected. The present invention improves the various drawbacks of the prior art and provides a large-capacity, yet small-sized bubble domain memory device.

The present invention will be explained below with reference to detailed drawings. FIG. 1 is a plan view of the element. Element 1 has a substrate coated with an orthoferrite film, a pattern (not shown) for trapping magnetic bubbles on its surface, and connecting terminals 2. and so on.

FIG. 2 shows a conductor lead 4 formed on the surface of a polyimide film 3 by chemical etching and connected to an element 1. Both ends 4a and 4b of the lead protrude in a cantilevered manner from the polyimide film, and the negative end 4a is connected to the connection terminal 2 of the element 1, and the other end 4b is connected to a connection part of a package (not shown). FIG. 3 shows a first coil 5 for generating a rotating magnetic field, which is made of a coated copper wire 5a coated with a heat bonding type adhesive. FIG. 4 shows a state in which the first coil 5 of FIG. 3 is assembled into the element 1 to which the lead 4 of FIG. 2 is attached. FIG. 5 shows a state in which the lead 4 shown in FIG. 4 is bent onto the first coil 5. As shown in FIG. FIG. 6 shows a state in which the first coil 5 shown in FIG. 5 is assembled, the leads 4 are bent, and the second coil 6 is assembled. FIG. 7 is a partially cutaway top view showing the state in which the package 7 is attached to a DIL (dual in-line) type package 7 after being assembled as shown in FIG. 6. In the package, the connecting portion 9 of the pin 8 is electrically connected to one end 4b of the lead 4 of the assembled structure as shown in FIG. Also, within this package 7 is a magnet 10 that applies a bias magnetic field in the axial direction of the rotating magnetic field, and a yoke 11 protrudes from both poles of the magnet 10. 8 is a side view of the bubble memory device shown in FIG. 7, and FIG. 9 is a partially cutaway side view of another embodiment. Further, FIG. 10 is a top view of FIG. 9. In another embodiment, a magnet 10 and a yoke 11 are attached to the outside of the package 7 for the purpose of changing the strength of the bias magnetic field depending on the characteristics of the element 1. Next, the content of the present invention will be explained along with the manufacturing process of a bubble domain memory device.

The main components of the present invention are an element 1, a lead 4, a first coil 5, a second coil 6, a yoke 11 with a magnet 10, and a package 7. Connection terminals 2 are arranged on the element 1 . This connection terminal 2 has a bump-like shape made of Cu, Au, Ni, etc. on an Al or Ni conductor, and is aligned with the plating layer of Au, sn, Nl, etc. applied to the lead 4. It is connected by thermo-compression bonding through 1. FIG. 2 shows a state in which the lead 4 is connected to the element 1. Ends 4a and 4b of the lead 4 laid on the polyimide film 3 protrude from the end of the polyimide film 3, and one end is connected to the element 1. It is connected to the connection terminal 2 of 1 in the manner described above. On the other hand, the other end is connected to the connecting portion 9 of the package 7 when it is assembled into the package 7. After the leads 4 are connected, a first coil 5 for generating a rotating magnetic field is attached. This first coil 5 is a so-called high-wire wire in which a heat-softening adhesive is applied to the upper surface of an insulating film, and after being wound into a predetermined shape, it is formed and heated with electricity, as shown in Fig. 3. It is shaped like this. This is assembled into the leaded element 1 shown in FIG. This state is shown in FIG. A portion of the element 1 is covered with a first coil 5. Next, the polyimide film 3 of the lead 4 is bent and processed as shown in FIG. , After that, when a second coil 6 for generating a rotating magnetic field is attached, the shape becomes as shown in FIG. Lead 4 is the first coil 5
and the second coil 6. The product assembled in this way is stored in a package cage 1. FIG. 7 shows an example of a method of storing the product in a package, and shows the internal structure of the DIL type package. As can be seen in FIG. 8, conductor pins 8 are arranged in rows on both sides of the package 7, the ends of which extend into the interior of the package and form connection portions 9. A magnet 10 and a yoke 11 are arranged inside the package 7 to generate a bias magnetic field applied in the axial direction of the rotating magnetic field. The leads 4 and the ends of the first coil 5 and the second coil 6, which are connected to the previously assembled element 1, are connected to the connecting portions 9 of the package, respectively. In this way, a bubble domain memory device is completed. 9 and 10 show another embodiment of the present invention, in which a yoke 11 and a magnet 10 are attached to apply a bias magnetic field from the outside of the package 7. The package 7 has a notch 12 at a portion into which the magnet 10 is inserted. Further, the yoke 11 is fixed to the package cage 7 with screws 13. The effects of the present invention have many features over conventional structures. The major structural advantage is that since the coil is attached directly to the element, it is small and requires less current.
The driver circuit has become simpler. In addition, if the element is not placed in the same plane as the rotating magnetic surface, noise will overlap with the read signal, but in the present invention, the coil is formed after being wound up, so if the element is inserted into the coil, the magnetic field of the coil will Since the direction and the surface of the element are perfectly matched, the generation of noise can be kept to a minimum. In addition, in the conventional technology, wiring of elements was done by wire bonding,
Since the lead paths do not have the same mechanical shape, a difference occurs between the voltages excited in the two wires, causing noise. However, in the present invention, since a conductor with a polyimide film pattern is used, it is possible to easily make the shape of the two conductors the same in the ring of the electric circuit. Therefore, the voltages excited in these two conductors are the same, which has the effect of significantly reducing noise in the read signal. Further, the connection between the element and the conductor is a method that does not use conductive wires, and it is natural that simultaneous connection at multiple points can be made, which has the effect of reducing the number of man-hours. Furthermore, the structure described in the other embodiments can be replaced with a magnet that provides a bias magnetic field, so the magnet can be selected according to the characteristics of the element, which has the effect of setting advantageous operating conditions during driving. be. As described above, the present invention is superior in that it has many effects compared to devices based on conventional systems.

[Brief explanation of drawings]

Figure 1 is a plan view showing an example of a bubble domain element, Figure 2 is a plan view showing an example of a bubble domain element.
The figure shows a state in which leads are attached to the element, Figure 3 shows an example of a coil that generates a rotating magnetic field, Figure 4,
5, 6, and 7 are explanatory diagrams showing how the bubble domain device of the present invention is assembled, and FIG. 8 is a side view showing an embodiment of the bubble domain memory device of the present invention.
FIGS. 9 and 10 are diagrams showing another embodiment of the present invention. 1...Element, 2...Connection terminal, 3...
...Polyimide film, 4...Lead,
5...First coil, 6...Second coil, 7...Package, 8...Pin, 9...Connection Part, 10...Magnet, 11...Yoke, 12...Notch part, 13...Screw.

Claims (1)

[Claims] 1. In a bubble domain memory device in which a magnetic bubble domain is driven by a rotating magnetic field, a wiring member connected to a bubble domain memory element is made of a plastic film and a patterned flexible pattern formed on the film. The wiring member is made of a certain conductor, and the wiring member is fitted into a gap between two coils that are perpendicular to each other to obtain a rotating magnetic field, and is drawn out to fix the coil and the bubble domain memory element, thereby forming a DIL type. A bubble domain memory device characterized by being housed in a package and comprising a magnet for generating a bias magnetic field. 2 The flexible conductor is plated with Au, Sn, Ni, etc., and the valve domain memory element is plated with Au, Cu, or a material that easily forms an alloy with the conductor. 2. The bubble domain memory device according to claim 1, wherein the bubble domain memory device is connected to an element without using a separate conducting wire. 3. The bubble domain memory device according to claim 1, wherein the magnet for generating a bias magnetic field used to drive the bubble domain memory has a yoke disposed outside the rotating magnetic field generating coil. 4. The bubble domain memory device according to claim 3, wherein the yoke is located outside the dual in-line package and is attached in a structure to sandwich the package. 5. The bubble domain according to claim 1, wherein the dual in-line package has a notch shaped to hold a magnet for generating a bias magnetic field, and the package, magnet, and yoke are fixed to each other. memory device.