JPS6212986A - Package of magnetic bubble memory device - Google Patents

Abstract

PURPOSE:To adjust a bias magnetic field supplied to a bubble memory chip surface with use of a magnet by providing through holes for connecting a shield pattern and a pattern for an earth formed on a peripheral surface of a ceramic plate of the rear side on a printed circuit board and its rear side ceramic plate. CONSTITUTION:Shield pattern 2a, 2b formed on a ceramic plate 1 of the first layer and shield patterns 11a, 11b formed on a ceramic plate 10 of the third layer are connected by through holes 3a-3c and the shield pattern 11a, 11b formed on the ceramic plate of the third layer are connected to a pattern 8 for an earth through through holes 9a, 9b. Thereby, the shield patterns 2a, 2b, 11a, 11b performing a magnetic shield with respect to a vertical component generating a driving coil for a rotating magnetic field are used also as the pattern for the earth, so that a whole of the package is made compact and a vertical magnetic field generated in the driving coil can be made small by a magnetic shield effect.

Description

Detailed Description of the Invention (Field of Application of the Invention) The present invention is suitable for reducing the thickness of a magnetic bubble memory device package, particularly the substrate mounted on the device, and miniaturizing the device itself, and is suitable for shielding the perpendicular component of a rotating magnetic field. The present invention relates to a possible package of magnetic bubble memory chips.

(Background of the Invention) In conventional single-chip magnetic bubble memory devices, the chip is mounted on a printed wiring board made of plastic or ceramic, as introduced in "Magnetic Bubble" published by Ohm Co., Ltd., page 134, for example. However, no consideration has been given to the effect of shielding the perpendicular component of the rotating magnetic field. Therefore, when a conductor is interlinked with a time-varying magnetic flux such as an alternating magnetic field, eddy currents flow and an eddy current product occurs. In particular, in the case of ferromagnetic materials, the magnetic flux is large, so in addition to eddy current loss, a skin effect occurs in which changes in magnetization are hindered by the magnetic field caused by eddy currents, and due to this skin effect, μ can now be changed to the magnetic permeability of the conductor, ω is the angular frequency, σ
When is the conductivity of the conductor and f is the frequency, the change in magnetization is attenuated at a thickness that is 1/1 of the surface of the conductor. Therefore, even if you use a normal ferromagnetic copper pattern and sandwich the top and bottom with one pattern grounded, the copper pattern can still be used as a ground, but due to the linkage magnetic flux generated by the rotating magnetic field generation drive coil. Eddy current loss is significant,
There is a drawback that the change in magnetization is attenuated due to the skin effect, which impedes the rotating magnetic field and affects the operating margin of the chip. Furthermore, when the capacitance of the chip becomes large and the number of wiring patterns increases, if only one side of the board can be used, the entire board becomes small and the magnetic bubble device becomes larger.

(Object of the Invention) An object of the present invention is to provide a package for a magnetic bubble memory device that eliminates the above-mentioned conventional drawbacks and allows accurate adjustment of the bias magnetic field supplied to the bubble memory chip surface using a magnet.

(Summary of the Invention) In order to achieve the above-mentioned object, the present invention provides a plurality of ceramic plates for mounting a magnetic bubble memory chip such that a printed circuit board made of ceramic is inserted therein, and the bubble memory chip is mounted on the printed circuit board. A wiring pattern and a grounding pattern are provided to be connected to the bubble memory chip and connected to both the front and back surfaces of the printed circuit board, and a plurality of core ceramic plates are connected to the plurality of ceramic plates and the printed circuit board. A through hole is provided to connect the shield pattern formed on the circumferential surface of the printed circuit board and the ceramic plate on the back side thereof, and the shield pattern formed on the circumferential surface of the ceramic plate on the back side and the grounding pattern are connected to the printed circuit board and the ceramic plate on the back side thereof. It is characterized by providing a through hole for connection.

(Embodiments of the Invention) Hereinafter, FIGS. 1 and 2 showing embodiments of the present invention will be described. FIG. 1 is a perspective view of a magnetic bubble memory device vanocage showing an embodiment of the present invention, FIG. 2 is a cross-sectional front view taken along the line A-A' in FIG. The first layer of the ceramic plate is shown, the figure (A) shows the second layer of the ceramic plate, that is, the substrate, and the figure (c) shows the third layer of the ceramic plate. In the figure, reference numeral 1 denotes a first layer of ceramic plate, which is thicker than a normal copper plate and has a shield pattern 2α on its upper and peripheral surfaces.

2h, a through hole 3α passing through in the vertical direction near the peripheral end is formed, and a ring-shaped cap 4 for sealing a bubble memory chip 6, which will be described later, is inserted into the inner peripheral surface of this through hole 3α. are doing. Reference numeral 5 designates a second layer ceramic plate, that is, a substrate, on the upper surface of which a bubble memory chip 6 is fixed in a central recess 5α, and a wiring pattern 7a is provided at one end of this bubble memory chip 6 so as to be connected thereto.
, and a grounding pattern 8 is formed at the tip thereof,
A wiring pattern 7h sealed in a hole 5b vertically penetrating the second layer ceramic plate 5 is formed so as to be connected to an end of the wiring pattern 7a, and one end of the wiring pattern 7b is connected to the bottom surface of the wiring pattern 7b. A wiring pattern 7c is formed which connects to the bubble memory chip 6 and reaches a position below the end of the bubble memory chip 6, which is the other end. Further, the second layer ceramic plate 5 has a through hole 3b penetrating in the vertical direction at one end thereof at a position connected to the through hole 3α, and a through hole 3b penetrating in the vertical direction at the other end at a position connected to the above earthing pattern 8. A through hole 9α passing through is formed. 10 is the third layer ceramic plate, and the above-mentioned first layer ceramic plate 1
shield patterns 11α and 11h are formed on the lower and circumferential surfaces, respectively, and through holes 3c and 9h that penetrate in the vertical direction are formed at positions connected to the through holes 3h and 9α. is forming. In addition, a drive coil (not shown) is provided on the second layer ceramic board 5 so as to surround the second layer ceramic board 5 so as to be connected to the wiring patterns 7α and 7b, and a drive coil (not shown) is provided for opening and closing the gate. A conductor pattern (not shown) is provided.

With the above configuration, voltage pulses are supplied to the gate opening/closing conductor pattern necessary for inputting the output signal from the bubble memory chip 6 and transferring the magnetic puzzle (not shown) in the bubble memory chip 6. Since the wiring patterns 7α, 7b, and 7c that perform these functions are formed on both the upper and lower surfaces of the second layer ceramic plate 5, the shape of the second layer ceramic plate 5 can be made smaller.

Further, the shield patterns 2α, 2iS formed on the first layer ceramic plate 1 and the shield patterns 11α, 11h formed on the third layer ceramic plate 10 are connected by through holes 3α, 5b, 3c, and shield patterns 11α and 11b formed on the third layer ceramic plate.
Grounding pattern 8 via through holes 9α and 9A
The above-mentioned shield patterns 2α, 2b are connected to K and thereby perform magnetic shielding against the vertical component that generates the rotating magnetic field drive coil.

Since 11α and 11h are also used as grounding patterns, it is possible to downsize the entire package and reduce the vertical magnetic field generated in the drive coil due to the magnetic shielding effect. Therefore, the bias magnetic field supplied to the surface of the bubble memory chip 60 can be adjusted more accurately using a magnet.

(Effects of the Invention) As described above, the present invention can reduce the size of the entire package and accurately adjust the bias magnetic field supplied to the bubble memory chip surface.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a magnetic bubble memory device package showing an embodiment of the present invention, and FIG. 2 is a sectional front view taken along the line AA' in FIG. 1・・・・・・・・・・・・・・・・・・・・・・・・
・・・・・・・・・First layer ceramic plate 2α
, 2A, 11α, 11h... Shield pattern 5B, 5h, 5c, 9a, 9b ===Through hole 4.
・・・・・・・・・・・・・・・・・・・・・・・・
・・・・・・・・・Cap 5・・・・・・・・・・・・
・・・・・・・・・・・・・・・・・・・・・・・・
・Second layer ceramic plate 6・・・・・・・・・・・・
・・・・・・・・・・・・・・・・・・・・・ Bubble memory chips 7α, 7b, 7c・・・・・・・・・
......Wiring pattern 8...
・・・・・・・・・・・・・・・・・・・・・・・・
・Earth pattern 10, =・・・・・・・・・・・・
・・・・・・・・・・・・・・・・・・Third layer ceramic plate bundle 1 diagram

Claims (1)

[Claims] In order to mount the magnetic bubble memory chip, a printed circuit board made of ceramic and a plurality of ceramic plates inserted on the front and back sides of the printed circuit board are provided, and the bubble memory chip and the bubble memory chip are mounted on the printed circuit board. A wiring pattern connected to and connected to the front and back surfaces of the printed circuit board and a grounding pattern are provided on the plurality of ceramic plates and the printed circuit board, and on the circumferential surface of the plurality of ceramic plates. A through hole is provided to connect the formed shield pattern, and the shield pattern and the grounding pattern formed on the circumferential surface of the ceramic plate on one side are connected to the printed circuit board and the ceramic plate on one side of the printed circuit board. A package for a magnetic bubble memory device characterized by having a through-hole.