JP2909790B2 - Superconducting detection coil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a superconducting quantum interference device (Superconductor) applied to a high-sensitivity magnetic sensor.
ing Quantum Interference
Device: abbreviated as SQUID).

[0002]

2. Description of the Related Art SQUIDs have been applied to the detection of minute magnetic fields. In the SQUID magnetometer, a bobbin type detection coil formed of a superconducting wire is often used. FIG.
Reference numeral 0 denotes a configuration of a conventional primary differential bobbin type detection coil. 11 is a bobbin, 12 is a superconducting coil wire, 13
And 14 are damping resistors. A superconducting coil wire 12 is disposed in a groove formed in the bobbin 11 so that the upper and lower coils are wound in opposite directions.
Represents a structure in which the superconducting coil wire 12 is connected to the electrode 13 to which is connected.

FIG. 11 is a diagram showing a configuration of a conventional secondary differential bobbin type detection coil. The upper and lower coils are wound in the same direction, and the middle coil is reversely wound with twice the number of turns of the upper and lower coils. Primary differential bobbin type detection coil, 2
Both the secondary differential bobbin type detection coils have a structure in which the wires other than the coils are stranded, and prevent the magnetic flux from interlinking in the wires. The primary differential bobbin type detection coil detects a difference between a magnetic field signal detected by an upper coil and a magnetic field signal detected by a lower coil, that is, a magnetic field gradient. The secondary differential bobbin type detection coil detects a magnetic field gradient which is a difference between a magnetic field gradient detected by an upper coil and an intermediate coil and a magnetic field gradient detected by an intermediate coil and a lower coil.
Therefore, coil area accuracy, shape accuracy, mutual position accuracy, mutual parallel accuracy, and the like affect the magnetic field gradient sensitivity.

[0004]

In the above-mentioned conventional primary differential bobbin type detection coil, machining accuracy is required for the groove of the bobbin for arranging the superconducting coil wire. A triangular gap is formed at the boundary between the circular coil part and the stranded wire, and it is not easy to improve the area accuracy, shape accuracy, mutual position accuracy, and mutual parallel accuracy of the upper and lower two coils, and the magnetic field gradient There was a problem that the reproducibility of sensitivity and characteristics was reduced, and there was a problem that skill was required for the manufacturing operation and the manufacturing was not easy. Also, when connecting a damping resistor in parallel with the detection coil, it is difficult to connect the resistor directly to the detection coil, and since the resistor is connected near the portion where the SQUID and the detection coil are connected, the workability is not good. Was.

[0005]

According to the present invention, in order to solve the above-mentioned problems, a superconducting wiring pattern partially having a substantially U-shaped wiring portion, or a superconducting wiring pattern and a resistor are formed. The flexible substrate is rolled into a cylindrical shape, and a substantially U-shaped wiring portion is formed to form a cylindrical wiring pattern to form a superconducting detection coil.

[0006]

According to the structure of the superconducting detection coil as described above, the detection coil wiring pattern and the resistance pattern are formed by a normal board wiring pattern forming technique, and the superconducting element is easily formed by forming the flexible substrate into a cylindrical shape. A detection coil can be manufactured, the area accuracy, shape accuracy, mutual position accuracy, mutual parallel accuracy of the upper and lower two coils can be improved, and the absolute accuracy of the resistance value and a plurality of superconducting detection coils The relative accuracy between them can be improved.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram illustrating a wiring pattern on a flexible substrate of a primary differential bobbin type detection coil according to a first embodiment of the present invention. 1 is a flexible substrate, 2 is a superconducting wiring pattern, 3 is an electrode, 4 is a resistance wiring, and a flexible substrate 1 is a polyimide substrate, a superconducting wiring pattern 2
And lead 3 (Pb-Sn) plated wiring as the electrode 3,
Niobium (Nb) sputtered film wiring, lead indium (Pb-
In) A deposited film wiring is used, but another superconducting thin film wiring or a superconducting thick film wiring may be used. As a buffer layer of the Pb-Sn plating film, a resistance material such as copper (Cu) or palladium (Pd) is used, but another high resistance material can be used. The resistance wiring 4 is made of the same resistance material as the buffer layer of the Pb-Sn plating film.

By winding one turn so that the portion indicated by A in FIG. 1 and the portion indicated by B overlap, one of the configurations shown in FIG.
A first-order differential detection coil having a winding can be configured. The arrow in FIG. 3 indicates the winding direction of the coil. Also, by winding two turns so that A, C and B in FIG. 1 overlap, a two-turn primary differential detection coil having the structure shown in FIG. 4 can be formed. The arrow in FIG. 4 indicates the winding direction of the coil.

FIG. 2 is a sectional view showing the structure of a first-order differential bobbin type detection coil according to the first embodiment of the present invention. 6 is a bobbin, 7 is a cover. 1 shows a configuration in which the flexible substrate 1 on which the superconducting wiring pattern shown in FIG. 1 is formed is wound around a bobbin 6 and a cylindrical cover 7 is arranged. As the material of the bobbin 6, a cylindrical material or a cylindrical material such as FRP, glass, Teflon or the like is used.
A cylindrical material such as P, glass, and Teflon is used.

FIG. 5 is a diagram showing a wiring pattern on a flexible substrate of a secondary differential bobbin type detection coil according to a second embodiment of the present invention. The materials of the flexible substrate 1, the superconducting wiring pattern 2, the buffer layer of the Pb-Sn plating film, the electrode 3, and the resistance wiring 4 are the same as those in the first embodiment. A portion where the wiring pattern shown by A in FIG. For example, after the lower superconducting film wiring is formed, it is covered with an insulating material such as urethane.

By winding two turns so that A, B, and C in FIG. 5 overlap, the number of turns in the upper, middle, and lower parts shown in FIG.
It is possible to configure a secondary differential detection coil having two windings, two windings, and one winding. The arrow in FIG. 6 indicates the winding direction of the coil. By winding four turns so that A, B, and C in FIG. 5 overlap, it is also possible to configure a secondary differential detection coil having two turns, four turns, and two turns in the upper, middle, and lower turns.

FIG. 7 is a view showing a wiring pattern on a flexible substrate of a primary differential bobbin type detection coil according to a third embodiment of the present invention. In FIG. 7, the length of the wiring between B-D and E-
The lengths of the wires between F are equal. The materials of the flexible substrate 1, the superconducting wiring pattern 2, the buffer layer of the Pb-Sn plating film, the electrode 3, and the resistance wiring 4 are the same as those in the first embodiment. At a position C exactly intermediate between A and B in FIG.
By making one turn so that D overlaps, one turn of the primary differential detection coil can be formed by two turns, thereby forming a two-turn primary differential detection coil.

In the superconducting wiring pattern 2 shown in FIG. 7, the wiring between A and E is slanted, and the length of the wiring between B and D is made equal to the length of the wiring between E and F. The upper and lower coils can be made to have exactly the same area when configured. Further, by winding the wiring so that the middle of the wiring between D and F overlaps the middle of the wiring between A and E in FIG. 7, the noise in the lateral direction of the detection coil can be removed.

FIG. 8 is a diagram showing a wiring pattern on a flexible substrate of a primary differential bobbin type detection coil according to a fourth embodiment of the present invention. The materials of the flexible substrate 1, the superconducting wiring pattern 2, the buffer layer of the Pb-Sn plating film, the electrode 3, and the resistance wiring 4 are the same as those in the first embodiment. The superconducting wiring pattern 2 is wired on both sides of the flexible substrate 1 or on different layers. The continuity between the superconducting wiring patterns on both sides or different layers is made by a superconductor by opening a contact hole 5 in the buffer layer and the flexible substrate 1. By winding one turn so that B overlaps A in FIG. 8, one turn of the primary differential detection coil,
The two turns constitute a two-turn primary differential detection coil.

FIG. 9 is a diagram showing a wiring pattern on a flexible substrate of a primary differential bobbin type detection coil according to a fifth embodiment of the present invention. The materials of the flexible substrate 1, the superconducting wiring pattern 2, the buffer layer of the Pb-Sn plating film, the electrode 3, and the resistance wiring 4 are the same as those in the first embodiment. The superconducting wiring pattern 2 is wired on both surfaces of the flexible substrate 1 or on different layers in the same manner as in the fourth embodiment.

As shown in FIG. 9, the superconducting wiring pattern between the electrodes 3 and A and B is connected to the front and back surfaces of the flexible substrate 1 or to different layers in order to eliminate horizontal noise. . One turn of the primary differential detection coil is formed by winding one turn so that D overlaps the position C exactly in the middle between A and B in FIG.
A first-order differential detection coil having a winding can be configured.

According to the structure of the superconducting detection coil as described above, by forming the flexible substrate on which the coil wiring pattern is formed into a cylindrical shape, the primary and higher-order differential superconductivity can be easily formed with an arbitrary number of turns. Detection coils can be manufactured, area accuracy of each coil, shape accuracy, mutual positional accuracy,
Mutual parallel accuracy can be improved. Further, the absolute accuracy of the damping resistance and the relative accuracy among the plurality of superconducting detection coils can be improved. By the above,
The magnetic field gradient sensitivity and the reproducibility of characteristics can be improved.

[0018]

As described above, according to the present invention, a superconducting detection coil can be easily formed by arranging a flexible substrate on which a superconducting film wiring and a resistance wiring are formed in a cylindrical shape to form a superconducting detecting coil. Coils can be manufactured,
The area accuracy, shape accuracy, mutual position accuracy, and mutual parallel accuracy of the upper and lower two coils can be improved, and the absolute accuracy of the damping resistor and the relative accuracy between a plurality of superconducting detection coils can be improved. As a result, the magnetic field gradient sensitivity and the reproducibility of characteristics can be improved.

[Brief description of the drawings]

FIG. 1 is a wiring pattern on a flexible substrate of a primary differential bobbin type detection coil according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a configuration of a primary differential bobbin type detection coil according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a first-order primary differential detection coil.

FIG. 4 is a diagram showing a configuration of a two-turn primary differential detection coil.

FIG. 5 is a wiring pattern on a flexible board of a first-order differential bobbin type detection coil according to a second embodiment of the present invention.

FIG. 6 is a diagram showing a configuration of a secondary differential detection coil in which the upper, middle, and lower detection coils have one turn, two turns, and one turn.

FIG. 7 is a wiring pattern on a flexible board of a primary differential bobbin type detection coil according to a third embodiment of the present invention.

FIG. 8 is a wiring pattern on a flexible board of a first-order differential bobbin type detection coil according to a fourth embodiment of the present invention.

FIG. 9 is a wiring pattern on a flexible board of a first-order differential bobbin type detection coil according to a fifth embodiment of the present invention.

FIG. 10 is a diagram showing a configuration of a conventional primary differential bobbin type detection coil.

FIG. 11 is a diagram illustrating a configuration of a conventional secondary differential bobbin type detection coil.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flexible board 2 Superconducting wiring pattern 3 Electrode 4 Resistance wiring 5 Contact hole 6 Bobbin 7 Cover 11 Conventional bobbin 12 Superconducting coil wire 13 Conventional electrode 14 Conventional damping resistance

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-199985 (JP, A) JP-A-1-174904 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01R 33/00-33/18 H01F 6/00-6/06 H01L 39/00-39/24

Claims (2)

(57) [Claims] 1. A flexible substrate on which a superconducting wiring pattern having a substantially U-shaped wiring portion is formed at least partially in a cylindrical shape, wherein the substantially U-shaped wiring portion has at least a pair of upper and lower cylindrical shapes. A superconducting detection coil configured to form a wiring pattern. 2. A superconducting wiring pattern having a substantially U-shaped wiring portion in at least a part thereof, and a flexible substrate on which a resistor electrically connected in parallel with the superconducting wiring pattern is formed. A superconducting detection coil, wherein the rounded, substantially U-shaped wiring portion forms at least a pair of upper and lower cylindrical wiring patterns.