JP5937471B2 - Magnetostatic wave element and magnetostatic wave device - Google Patents

Description

  The present invention relates to a magnetostatic wave element and a magnetostatic wave device used for a resonator constituting a filter.

2. Description of the Related Art Conventionally, devices using surface acoustic waves (SAWs) have been widely used as devices for taking out electrical signals in a specific frequency band in wireless communication devices such as mobile phones.

The SAW device has a structure in which an IDT (InterDigital Transducer) electrode is formed on a piezoelectric substrate.

  In recent years, wireless communication devices and the like have come to use higher-frequency electrical signals, and for example, devices that use a frequency band of 2.5 GHz or more are also considered. Along with this, filters and the like used for mobile phones are also required to support high frequencies.

  However, in a device using SAW, when trying to cope with a high frequency exceeding 2.5 GHz, the interval between the electrode fingers constituting the IDT electrode must be made very narrow, and a SAW device can be manufactured with high yield. It becomes difficult to do. In addition, since the electrode fingers themselves become smaller, the electrical resistance increases, making it difficult to satisfy the required characteristics such as filter insertion loss.

  On the other hand, devices using magnetostatic waves propagating in a magnetic film instead of using SAW have been known. A device using magnetostatic waves includes an element substrate, a magnetic film formed on the main surface of the element substrate, and an excitation electrode formed on the magnetic film (see, for example, FIG. 7 of Patent Document 1). .

  A device using such a magnetostatic wave has a higher propagation speed of the magnetostatic wave than that of the SAW, and therefore can easily cope with higher frequencies than a device using the SAW.

JP-A-7-220923

  However, in conventional devices using magnetostatic waves, sufficient consideration has not been made from the viewpoint of use as a resonator for constituting a filter, and it is difficult to say that any of them can provide sufficient resonance characteristics. .

  Therefore, it is desired to provide a magnetostatic wave element and a magnetostatic wave device that can obtain sufficient resonance characteristics.

A magnetostatic wave element as one aspect of the present invention includes an element substrate, a magnetic film located on a main surface of the element substrate, and an excitation electrode partly located on the magnetic film. The excitation electrode includes a first bus bar positioned on the main surface of the element substrate, a second bus bar positioned on the main surface of the element substrate so as to face the first bus bar, At least one first electrode finger having an end connected to the first bus bar and extending in a first direction from the first bus bar toward the second bus bar, and one end connected to the second bus bar and the first bus bar At least one second electrode finger extending in a direction opposite to the one direction, and a region between the first bus bar and the second bus bar, a first bus bar, and the main surface of the element substrate. The area between the second bus bar The magnetic film is provided only in the first region when a region extending in a second direction orthogonal to one direction is a first region and a region other than the first region is a second region. is there.

  A magnetostatic wave device as one aspect of the present invention includes the magnetostatic wave element described above, a mounting substrate on which the magnetostatic wave element is mounted, and a resin layer that covers the magnetostatic wave element.

  In the magnetostatic wave element and magnetostatic wave device configured as described above, the magnetic film is provided only in the first region, which is the region between the first bus bar and the second bus bar, and therefore the first bus bar and the second bus bar. The generation of unnecessary magnetic resonance or the generation of magnetostatic waves in another mode in the region immediately below is suppressed, and the resonance characteristics can be improved.

1 is a plan view of a magnetostatic wave device according to a first embodiment of the present invention. It is sectional drawing in the A-A 'line of FIG. (A) to (c) is a cross-sectional view illustrating a method for manufacturing the magnetostatic wave element of FIG. 1 is a cross-sectional view of a magnetostatic wave device according to a first embodiment of the present invention. It is a top view of the magnetostatic wave element which concerns on the modification of 1st Embodiment. It is a top view of the magnetostatic wave element which concerns on the 2nd Embodiment of this invention. It is sectional drawing of the magnetostatic wave element which concerns on the 3rd Embodiment of this invention. It is a top view of the magnetostatic wave element which concerns on the 4th Embodiment of this invention. It is a cross-sectional schematic diagram in the iX-iX line of the magnetostatic wave element shown in FIG.

  Hereinafter, magnetostatic wave elements and magnetostatic wave devices according to embodiments of the present invention will be described with reference to the drawings. Note that the drawings used in the following description are schematic, and the dimensional ratios and the like on the drawings do not necessarily match the actual ones.

  In the second and subsequent embodiments, configurations that are the same as or similar to those already described are denoted by the same reference numerals as those already described, and illustration and description may be omitted.

<First Embodiment>
(Configuration of magnetostatic wave element)
FIG. 1 is a plan view of a magnetostatic wave element 1 as a resonator according to the first embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line AA ′ of FIG.

  The magnetostatic wave element 1 includes an element substrate 3, a magnetic film 2 provided on the main surface 3 a of the element substrate 3, an excitation electrode 5 provided on the main surface 3 a of the element substrate 3 and the main surface 2 a of the magnetic film 2. And have. Further, on the main surface 3 a of the element substrate 3, a pad 4 that is electrically connected to the excitation electrode 5 and a connection wiring 11 that connects the excitation electrode 5 and the pad 4 are formed. Although FIG. 1 shows an example in which one excitation electrode 5 is provided on the main surface 3 a of the element substrate 3, a plurality of excitation electrodes 5 may be formed on the main surface 3 a of the element substrate 3.

  The element substrate 3 is a substrate made of a nonmagnetic material such as a silicon substrate or a gadolinium-gallium garnet (GGG) substrate. The element substrate 3 is formed in a rectangular parallelepiped shape, for example. The size of the element substrate 3 may be set as appropriate. For example, the thickness (Z direction) is 0.2 mm to 0.5 mm, and the length of one side (x direction or y direction) is 0.5 mm. ~ 3mm.

  A magnetic film 2 is formed on the main surface 3 a of the element substrate 3. The magnetic film 2 is made of, for example, nickel iron alloy (permalloy), yttrium-iron-garnet (YIG), or the like. The thickness of the magnetic film 2 is, for example, 20 nm to 100 nm. A DC magnetic field is applied to the magnetic film 2 in a predetermined direction, whereby the magnetic film 2 is magnetized.

  As will be described later, the magnetic film 2 is formed only in a specific region of the main surface 3a of the element substrate 3.

The excitation electrode 5 is an IDT (Interdigital Transducer) electrode, for example, and has a pair of comb-like electrodes. Specifically, the excitation electrode 5 has a first bus bar 6 extending in the x direction, a second bus bar 7 disposed opposite to the first bus bar 6 and extending in the x direction, and one end at the first bus bar. 6, a plurality of first electrode fingers 8 extending in the first direction (y direction) from the first bus bar 6 toward the second bus bar 7, and one end connected to the second bus bar 7 and the second bus bar 7 has a plurality of second electrode fingers 9 extending in a direction (−y direction) from 7 to the first bus bar 6.

  In the magnetostatic wave element 1, the plurality of first electrode fingers 8 and the plurality of second electrode fingers 9 are alternately positioned one by one when viewed in the x direction. Are arranged as follows. In other words, the comb-like electrode made up of the first bus bar 6 and the plurality of first electrode fingers 8 and the comb-like electrode made up of the second bus bar 7 and the plurality of second electrode fingers 9 They are arranged so as to mesh with each other.

  If the wavelength of the magnetostatic wave propagating through the magnetic film 2 is λ, the distance p between the centers of the first electrode finger 8 and the second electrode finger 9 is set to λ / 2, for example. Specifically, the center distance p is, for example, 2.5 μm to 12.5 μm. Further, different potentials are applied to the first bus bar 6 and the second bus bar 7 when the magnetostatic wave element 1 is used.

  Since FIG. 1 and the like are schematic diagrams, a pair of comb-like electrodes having several electrode fingers is shown, but actually a plurality of pairs of comb-teeth having more electrode fingers than this is shown. An electrode may be provided.

  The excitation electrode 5 is made of, for example, an Al alloy such as Al or an Al—Cu alloy, or a conductive material such as Cu. The thickness of the excitation electrode 5 is, for example, 100 to 500 nm.

  Here, in the main surface 3a of the element substrate 3, the region between the first bus bar 6 and the second bus bar 7 and the region between the first bus bar 6 and the second bus bar 7 are extended in a direction parallel to the x direction. The magnetic film 2 is provided only in the first region T1 when the region is the first region T1. By providing the magnetic film 2 in the first region T1, most of the first electrode fingers 8 and the second electrode fingers 9 are arranged on the magnetic film 2.

When a current flows through the plurality of first electrode fingers 8 and the plurality of second electrode fingers 9 arranged at a predetermined interval on the main surface 2a of the magnetic film 2 magnetized in a predetermined direction, a high frequency is generated around each electrode finger. Magnetic field is generated. Then, in the magnetic film 2, a precession occurs in the magnetic moment due to the electron spin, and a magnetostatic wave propagating in the x direction is generated via the precession.

The magnetostatic wave has three basic modes: a surface magnetostatic wave mode (MSSW), a volume forward magnetostatic wave mode (MSFVW), and a volume backward magnetostatic wave mode (MSBVW). Although present, either mode can be selected by selecting the direction of the DC magnetic field. Specifically, when the direction of the DC magnetic field is selected in a direction (y direction) parallel to the film surface (xy plane) of the magnetic film 2 and perpendicular to the propagation direction (x direction) of the magnetostatic wave, the magnetostatic wave of the MSSW Will occur. If the direction of the DC magnetic field is selected to be perpendicular to the film surface and also perpendicular to the propagation direction of the magnetostatic wave (z direction), an MSFVW magnetostatic wave is generated. If the direction of the DC magnetic field is selected to be parallel to the film surface and parallel to the propagation direction of the magnetostatic wave (x direction), an MSBVW magnetostatic wave is generated.

  The magnetostatic wave element 1 uses MSSW. That is, the DC magnetic field is applied in the y direction. The DC magnetic field is applied to the magnetic film 2 in the manufacturing process of the magnetostatic wave element 1, for example. Or you may make it provide a pair of magnet in the position which pinches | interposes the magnetic film 2 in the magnetostatic wave apparatus which mounts the magnetostatic wave element 1. FIG.

  In the magnetostatic wave element 1, since the magnetic film 2 is formed only in the first region T1, the first bus bar 6 and the second bus bar 7 are regions in the main surface 3a of the element substrate 3 other than the first region T1. It is located in a certain second region T2. That is, the magnetic film 2 does not exist under the first bus bar 6 and the second bus bar 7. If the magnetic film 2 is also formed under the first bus bar 6 and the second bus bar 7, a magnetostatic wave in a mode different from that of the MSSW is generated in the magnetic film 2 in that portion, or unnecessary magnetic resonance is generated. There is a concern that this may occur. Magnetostatic waves in a mode different from that of MSSW and unnecessary magnetic resonance cause generation of ripples and cause deterioration of resonance characteristics.

  On the other hand, according to the magnetostatic wave element 1, since the magnetic film 2 is formed only in the first region T1, generation of magnetostatic waves in a mode different from that of the MSSW in the regions immediately below the first and second bus bars, or Since generation of unnecessary magnetic resonance is suppressed, it is possible to suppress deterioration of resonance characteristics. Therefore, by configuring the filter using such a magnetostatic wave element 1, the characteristics of the filter can be improved, such as the loss can be kept small.

  Further, the end portion in the x direction of the magnetic film 2 is located outside by λ / 4 from the center of the electrode finger located at the end in the x direction among the plurality of first electrode fingers 8 and the plurality of second electrode fingers 9. Yes. That is, the distance d in FIG. 1 is λ / 4. As a result, magnetostatic waves are reflected so that standing waves are likely to be generated at the end of the magnetic film 2 in the x direction, and the resonance of the magnetostatic wave element 1 can be increased. The distance d may be changed within a range of λ / 4 + nλ (n is a positive integer).

2 is a cross-sectional view taken along line AA ′ of FIG. As shown in the figure, the excitation electrode 5 is covered with a protective layer 10. The protective layer 10 is made of, for example, silicon oxide (such as SiO ₂ ), aluminum oxide, zinc oxide, titanium oxide, silicon nitride, or silicon. The thickness of the protective layer 10 is, for example, about 1/10 (10 to 30 nm) of the thickness of the excitation electrode 5 or 200 nm to 1500 nm, which is thicker than the excitation electrode 5. Thereby, corrosion of the excitation electrode 5 is suppressed.

(Method for manufacturing magnetostatic wave element)
FIGS. 3A to 3C are cross-sectional views illustrating a method for manufacturing the magnetostatic wave element 1. 3A to 3C are cross-sectional views corresponding to the line AA ′ in FIG.

  3A to 3C corresponding to the method for manufacturing the magnetostatic wave element 1 is realized in a so-called wafer process. That is, thin film formation, photolithography, or the like is performed on the mother substrate that is to be the element substrate 3 by being divided, and then dicing is performed to form a large number of magnetostatic wave elements 1. However, in FIGS. 3A to 3C, only a portion corresponding to one magnetostatic wave element 1 is shown.

  As shown in FIG. 3A, first, the magnetic film 2 is formed on the main surface 3 a of the element substrate 3. For example, when the element substrate 3 is made of silicon and the magnetic film 2 is made of permalloy, a resist layer having an opening corresponding to the magnetic film 2 is formed on the main surface 3a of the element substrate 3, and a sputtering method is formed thereon. A permalloy film is formed by a thin film forming method such as vapor deposition. Thereafter, the magnetic film 2 is formed by removing the resist layer. The method for forming the magnetic film 2 is not limited to this, and a method using a metal mask, a method using dry etching, or the like is also possible.

  When the magnetic film 2 is thus formed, the magnetic film 2 is magnetized by, for example, disposing the element substrate 3 between a pair of electromagnets. The magnitude of the magnetic field applied at this time is, for example, 2 Oe to 1000 Oe.

Next, as shown in FIG. 3B, the excitation electrode 5 is formed. Specifically, first, a metal layer is formed on the main surface 3a of the element substrate 3 and the main surface 2a of the magnetic film 2 by a thin film forming method such as a sputtering method, a vapor deposition method, or a CVD (Chemical Vapor Deposition) method. Next, the metal layer is patterned by a photolithography method using a reduction projection exposure machine (stepper) and an RIE (Reactive Ion Etching) apparatus. Thus, the first bus bar 6 and the second bus bar 7 are formed on the main surface 3a of the element substrate 3, the first electrode finger 8 and the second electrode finger 9 are formed on the main surface 2a of the magnetic film 2, and the excitation electrode 5 Is completed. The pad 4 and the connection wiring 11 are formed simultaneously with the formation of the excitation electrode 5.

  Next, as shown in FIG. 3C, the protective layer 10 is formed. Specifically, first, a thin film to be the protective layer 10 is formed by an appropriate thin film forming method. The thin film forming method is, for example, a sputtering method or CVD. Next, a part of the thin film is removed by RIE or the like so that the pad 4 is exposed. Thereby, the protective layer 10 is formed. The magnetostatic wave element 1 is completed through the above steps.

(Configuration of magnetostatic wave device)
FIG. 4 is a cross-sectional view showing a magnetostatic wave device 51 according to the first embodiment of the present invention on which the magnetostatic wave element 1 is mounted.

  The magnetostatic wave device 51 includes a mounting substrate 53, a pad 55 provided on the mounting surface of the mounting substrate 53, a bump 57 disposed on the pad 55, and a magnetostatic wave mounted on the mounting surface via the bump 57. It has the element 1 and the resin layer 59 which seals the magnetostatic wave element 1. The magnetostatic wave device 51 constitutes a duplexer including at least one filter constituted by the magnetostatic wave element 1.

  The mounting substrate 53 is made of, for example, a ceramic substrate or a printed wiring board, and may be a single-layer board or a multilayer board having two or more layers. Internal wiring 52 is formed inside the mounting substrate 53. The internal wiring 52 forms, for example, an inductance and a capacitance. This inductance and capacitance constitute, for example, a duplexer matching circuit.

  External connection terminals 56 are provided on the lower surface of the mounting substrate 53. The external connection terminal 56 and the magnetostatic wave element 1 are electrically connected through a via conductor 54 formed inside the mounting substrate 53.

  The bumps 57 are in contact with both the pads 4 of the magnetostatic wave element 1 and the pads 55 of the mounting substrate 53. The bump 57 is formed of a metal that is melted by heating and bonded to the pad 4. The bump 57 is made of, for example, solder. The solder may be a solder using lead such as Pb—Sn alloy solder, or lead-free solder such as Au—Sn alloy solder, Au—Ge alloy solder, Sn—Ag alloy solder, Sn—Cu alloy solder, etc. It may be.

  The resin layer 59 is mainly composed of, for example, an epoxy resin, a curing material, and a filler. The resin layer 59 is also filled between the magnetostatic wave element 1 and the mounting substrate 53 so as to cover the entire magnetostatic wave element.

  As the magnetostatic wave device 51, for example, a duplexer module may be configured by mounting an IC or the like in addition to the magnetostatic wave element 1 on the mounting substrate 53.

(Modification)
FIG. 5 is a plan view showing a modification of the magnetostatic wave element 1 in the first embodiment.

  In the magnetostatic wave element 1 according to this modification, the other end of the first electrode finger 8 is connected to the second bus bar 7, and the other end of the second electrode finger 9 is connected to the first bus bar 6. Therefore, the excitation electrode 5 has a ladder shape as a whole. At this time, the center-to-center distance p4 between the first electrode finger 8 and the second electrode finger 9 is set to λ (λ is the wavelength of the magnetostatic wave), and is 4 μm, for example.

<Second Embodiment>
FIG. 6 is a plan view showing the magnetostatic wave element 20 of the second embodiment. The magnetostatic wave element 20 is different from the magnetostatic wave element 1 of the first embodiment in the formation region of the magnetic film 2.

  Specifically, in the magnetostatic wave element 20, the magnetic film 2 is provided only in the intersecting region T3 of the first electrode finger 8 and the second electrode finger 9 in the first region T1. By forming the magnetic film 2 only in the intersecting region T3 in this way, a desired region in the non-intersecting region (the region excluding the intersecting region T3 from the first region T1) between the first electrode finger 8 and the second electrode finger 9 is obtained. Generation of magnetostatic waves of a mode different from the mode (MSSW in the magnetostatic wave element 20) is suppressed, and the resonance characteristics can be further improved. The intersecting region is a region that overlaps the second electrode finger 9 when the first electrode finger 8 is extended in the magnetostatic wave propagation direction (x direction).

<Third Embodiment>
FIG. 7 is a cross-sectional view corresponding to FIG. 2 showing the magnetostatic wave element 30 of the third embodiment.

The magnetostatic wave element 30 further includes an insulating layer 31 interposed between the first electrode finger 8 and the second electrode finger 9 and the magnetic film 2. The insulating layer 31 is made of an insulating material such as SiO ₂ and covers the entire magnetic film 2. By providing the insulating layer 31, leakage of current flowing through the first electrode finger 8 and the second electrode finger 9 to the magnetic film 2 is suppressed. As a result, the resonance characteristics of the magnetostatic wave element 30 can be improved. The insulating layer 31 is particularly effective when the magnetic film 2 is made of a conductive magnetic material such as permalloy.

<Fourth Embodiment>
FIG. 8 is a plan view showing the magnetostatic wave element 40 of the third embodiment. The magnetostatic wave element 40 has a pair of frame electrodes 15 at both ends along the x direction of the excitation electrode 5.

  The frame-shaped electrode 15 includes a first linear portion 16 located adjacent to the electrode finger located at the end of the first electrode finger 8 and the second electrode finger 9, and a second line adjacent to the first linear portion 16. It is comprised from the connection part 18 which connects the both ends of the shape part 17, and the 1st linear part 16 and the 2nd linear part 17, and becomes a closed frame-like electrode as a whole.

  The width in the x direction of the first linear portion 16 and the second linear portion 17 is, for example, the same as the width of the first electrode finger 8 and the second electrode finger 9. Moreover, the length of the 1st linear part 16 and the 2nd linear part 17 in the y direction is more than the crossing width of the 1st electrode finger 8 and the 2nd electrode finger 9, for example.

  The first linear portion 16 of the frame-shaped electrode 15 is disposed at an interval of one wavelength of the magnetostatic wave from the electrode finger adjacent to the first linear portion 16. It is considered that the resonance characteristic of the magnetostatic wave element 40 is improved by arranging the first linear portion 16 at this position. The reason for this will be described with reference to FIG.

  FIG. 9 is a schematic cross-sectional view of a portion corresponding to the line iX-iX in FIG. In FIG. 9, a line L is a magnetostatic wave transmitted through the magnetic film 2 at a certain moment, “+” described in the magnetic film 2 is a portion corresponding to a magnetostatic wave peak, and “−” is a portion corresponding to a magnetostatic wave valley. It is. On the other hand, “±” shown in the first electrode finger 8, the second electrode finger 9, the first linear portion 16, and the second linear portion 17 is the current direction at that moment, and the “+” direction The current and the current in the direction of “−” indicate that they are flowing in opposite directions. In addition, the electric current which flows into the 1st electrode finger 8 and the 2nd electrode finger 9 is an alternating current, and the direction is changing alternately.

  The center-to-center distance p between the first electrode finger 8 and the second electrode finger 9 adjacent thereto is set to a distance corresponding to a half wavelength of the magnetostatic wave, that is, λ / 2, as in the first embodiment. ing. By arranging the first electrode finger 8 and the second electrode finger 9 in this way, a magnetostatic wave in the first mode is excited as shown in FIG. At this time, the magnetic field formed in the magnetic film by the electrode finger (second electrode finger 9 in FIG. 9) in which a current flows in the “+” direction is a magnetostatic wave in which a mountain is located under the electrode finger. Bond strongly. Similarly, the magnetic field formed in the magnetic film by the electrode finger (first electrode finger 8 in FIG. 9) in which a current flows in the direction of “−” is a magnetostatic wave in which a valley is located under the electrode finger. Bond strongly. The stronger the coupling between the magnetic field formed by the electrode finger on the magnetic film 2 and the magnetostatic wave, in other words, the greater the overlap integral between the magnetic field formed by the electrode finger on the magnetic film 2 and the magnetostatic wave, the greater the resonance.

  On the other hand, a current flows through the first linear portion 16 of the frame-shaped electrode 15 in the direction opposite to the current flowing through the second electrode finger 9 adjacent to the first linear portion 16. The current flowing through the first linear portion 16 is an induced current due to a change in the magnetic field formed around the first electrode finger 8 and the second electrode finger 9.

  Here, the first linear portion 16 is located away from the adjacent second electrode finger 9 by λ (= 2p). In other words, the center-to-center distance between the first linear portion 16 and the second electrode finger 9 is λ. In this case, a magnetostatic wave peak is located under the first linear portion 16 in which current flows in the direction of “−”, and the first linear portion 16 is formed in the magnetic film 2. The coupling between the magnetic field and the magnetostatic wave is weakened. That is, the overlap integral between the magnetic field formed by the first linear portion 16 and the magnetostatic wave in this portion becomes small. In such a place, the magnetostatic wave generated in the magnetic film 2 is difficult to leak to the outside, so that the propagation loss is reduced and the resonance characteristics of the resonator are improved.

  Further, if the distance from the first linear portion 16 of the second linear portion 17 connected to the first linear portion 16 is set to λ / 2 (= p), the lower side of the second linear portion 17 is also provided. Since the overlap integral between the magnetic field and the magnetostatic wave is small, it is considered that the leakage of the magnetostatic wave can be further suppressed.

FIG. 8 shows an example in which one resonator is disposed on the magnetic film 2. However, when a plurality of resonators are disposed on the magnetic film 2, the frame electrode 15 is disposed between adjacent resonators. By doing so, it is possible to suppress the magnetostatic wave of one resonator from propagating to the other resonator side by the frame electrode 15 and to suppress the interference of the magnetostatic wave between the resonators. .

  In the magnetostatic wave element 40, the first linear portion 16 is arranged at a position away from the adjacent second electrode finger 9 by λ. However, if it is arranged at a position away from mλ (m is a positive integer), the same It is thought that an effect is acquired.

  The present invention is not limited to the above embodiment, and may be implemented in various aspects, and the above-described embodiments may be combined as appropriate.

  For example, the modification in the first embodiment can be applied to the magnetostatic wave element 20 of the second embodiment and the magnetostatic wave element 30 of the third embodiment.

DESCRIPTION OF SYMBOLS 1 ... Magnetostatic wave element 2 ... Magnetic film 3 ... Element board | substrate 4 ... Pad 5 ... Excitation electrode 6 ... 1st bus bar 7 ... 2nd bus bar 8 ... 1st Electrode finger 9 ... second electrode finger 10 ... protective layer T1 ... first region T2 ... second region

Claims (7)

A magnetostatic wave element comprising: an element substrate; a magnetic film located on a main surface of the element substrate; and an excitation electrode partly located on the magnetic film,
The excitation electrode includes a first bus bar positioned on the main surface of the element substrate, a second bus bar positioned on the main surface of the element substrate so as to face the first bus bar, and one end of the first electrode. At least one first electrode finger connected to one bus bar and extending in a first direction from the first bus bar toward the second bus bar, and one end connected to the second bus bar and opposite to the first direction Including at least one second electrode finger extending in a direction;
Of the main surface of the element substrate, a region between the first bus bar and the second bus bar and a region between the first bus bar and the second bus bar are arranged in a second direction orthogonal to the first direction. When the extended region is the first region and the region other than the first region is the second region, the magnetic film is provided only in the first region, and the first bus bar and the second bus bar A magnetostatic wave element in which the magnetic film is not located below .   The magnetostatic wave element according to claim 1, wherein the magnetic film is provided only in an intersecting region of the first electrode finger and the second electrode finger in the first region.   An electrode finger interval between the first electrode finger and a second electrode finger adjacent to the first electrode finger is λ / 2 (λ is a wavelength of a magnetostatic wave propagating through the magnetic film), and the first finger of the magnetic film An end in two directions is located outside by λ / 4 + nλ (n is a positive integer) from an electrode finger located at an end in the second direction of the first electrode finger and the second electrode finger. Item 3. The magnetostatic wave device according to Item 1 or 2.   4. The magnetostatic wave element according to claim 1, further comprising an insulating layer interposed between the first electrode finger and the second electrode finger and the magnetic film. 5. A frame-like electrode disposed on at least one side of both ends of the excitation electrode in the second direction;
The electrode finger interval between the first electrode finger and the second electrode finger adjacent to the first electrode finger is λ / 2 (λ is the wavelength of the magnetostatic wave propagating through the magnetic film),
The frame-shaped electrode is adjacent to an electrode finger located at an end of the first electrode finger and the second electrode finger on the side where the frame-shaped electrode is disposed, and extends in the first direction. The distance between the first linear portion and the electrode finger located at the end on the side where the frame-shaped electrode is disposed is mλ (m is a positive integer). Magnetostatic wave element. The frame-shaped electrode has a second linear portion that is adjacent to the side opposite to the side where the excitation electrode is disposed with respect to the first linear portion and extends in the first direction,
The magnetostatic wave element according to claim 5, wherein an interval between the first linear portion and the second linear portion is λ / 2. The magnetostatic wave device according to any one of claims 1 to 6,
A mounting substrate on which the magnetostatic wave element is mounted;
A magnetostatic wave device comprising: a resin layer covering the magnetostatic wave element.

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