Electronic components

Abstract

The electronic component comprises: a piezoelectric substrate (1) and an interdigital capacitor (2) on top of the piezoelectric substrate. The interdigital capacitor comprises two electrodes (21, 22), each of the two electrodes comprising a plurality of fingers (23). The fingers each comprise an associated first metal layer (231) and at least some of the fingers comprise an associated second metal layer (232) on top of the first metal layer. For each finger comprising the first metal layer and the second metal layer, the width of the finger in the region of the associated first metal layer is greater than the width of the finger in the region of the associated second metal layer.

Description

Technical Field

[0001] An electronic component is defined. Background Art

[0002] One goal to be achieved is to define an electronic component with very stable performance. Summary of the invention

[0003] In accordance with at least one embodiment, an electronic component includes a piezoelectric substrate and an interdigital capacitor on top of the piezoelectric substrate. The interdigital capacitor includes two electrodes, each of the two electrodes includes a plurality of fingers. The fingers each include an associated first metal layer, and at least some of the fingers include an associated second metal layer on top of the first metal layer. For each finger that includes the first metal layer and the second metal layer, a width of the finger in a region of the associated first metal layer is greater than a width of the finger in a region of the associated second metal layer.

[0004] The invention is based in particular on the idea that an interdigitated capacitor on a piezoelectric substrate may generate unwanted surface acoustic waves (SAW) when supplied with an alternating voltage. By providing some of the fingers with a second metal layer having a width smaller than the first metal layer, the mass load along the surface of the piezoelectric substrate is changed. This hinders the excitation of oscillations of the fingers compared to the case where only the first metal layer is used for all fingers. Thus, the excitation of the surface acoustic waves is suppressed. Furthermore, with the additional second metal layer, the ohmic losses are reduced, so that the quality factor Q is improved.

[0005] The electronic component is preferably an electronic chip.The electronic component may comprise one or more interdigital capacitors as specified above and as specified below.

[0006] The piezoelectric substrate comprises or consists of a piezoelectric material, such as lithium tantalate, lithium niobate or quartz. The piezoelectric substrate may be self-supporting. In particular, the piezoelectric material may be provided as a bulk material.

[0007] In electronic components, capacitors are used, for example, for impedance matching. An interdigital capacitor is a capacitor in which two electrodes each include fingers arranged in a comb-like manner. The fingers of the electrodes are electrically connected to each other via a busbar. For example, each electrode of the interdigital capacitor includes at least two fingers or at least four fingers.

[0008] Both electrodes are located on the top side of the piezoelectric substrate. Each finger has a length measured along the main extension direction of the finger and a width measured perpendicular to the main extension direction of the finger. The length and width are both measured parallel to the top side of the piezoelectric substrate. The fingers preferably extend parallel or substantially parallel to each other.

[0009] For each finger, the length of the finger is greater than the width of the finger. For example, the length of each finger is at least two times, or at least five times, or at least ten times greater than its width. Here and hereinafter, the terms "length", "width" and "thickness" preferably correspond to average values.

[0010] The fingers of the first electrode and the fingers of the second electrode are crossed but electrically isolated from each other. In other words, the fingers of the first electrode and the fingers of the second electrode alternate along a direction perpendicular to the main extension direction of the fingers. During normal operation, the electrodes of the interdigitated capacitor are preferably at different potentials and are provided with an alternating voltage, for example.

[0011] The fingers each comprise an associated first metal layer. For each finger, the associated first metal layer is preferably formed continuously and / or integrally. The first metal layer is preferably in direct contact with the top side of the piezoelectric substrate. In particular, the first metal layer is in direct contact with the piezoelectric material of the piezoelectric substrate. For example, the first metal layer comprises or consists of copper, titanium or aluminum. The first metal layer of the fingers of the electrode may be continuous and / or may be formed integrally.

[0012] For each finger, the width in the region of the associated first metal layer is, for example, at least 1 μm or at least 5 μm or at least 10 μm. Alternatively or additionally, the width of the finger in the region of the associated first metal layer is in each case at most 100 μm or at most 50 μm or at most 30 μm. For each finger, the width in the region of the first metal layer is preferably constant within the limits of manufacturing tolerances. The width of the fingers in the region of the first metal layer is preferably the same for all fingers within the limits of manufacturing tolerances. In each case, the first metal layer preferably extends over the entire length of the associated finger.

[0013] In each case, the minimum distance between two adjacent fingers of the interdigital capacitor is preferably of the same order of magnitude as the width of the fingers in the region of the first metal layer. For example, the distance is at least 25% and at most 500% of the width of the fingers in the region of the first metal layer.

[0014] At least some of the fingers, preferably all of the fingers of the two electrodes, comprise a second metal layer on top of the first metal layer. The second metal layer may be in direct contact with the first metal layer. The first metal layer is arranged between the second metal layer and the piezoelectric substrate. The second metal layer is applied on top of the first metal layer and may be in direct contact with the first metal layer. The second metal layer may comprise copper, titanium or aluminum or consist of one or more of these materials. The second metal layer of each finger may be formed continuously and / or integrally.

[0015] In the region of the associated second metal layer, the fingers have a smaller width than in the region of the first metal layer. In other words, this means that in each finger, the width of the associated second metal layer is smaller than the width of the associated first metal layer. For example, in the region of the second metal layer, the width of the finger is at most 80% or at most 75% or at most 50% of the width in the region of the first metal layer. Alternatively or additionally, the width of the finger in the region of the second metal layer is at least 10% of the width in the region of the first metal layer. Preferably, the width of the finger in the region of the second metal layer is constant within the limits of manufacturing tolerances.

[0016] In other words, the width of the fingers comprising the first metal layer and the second metal layer follows a step-like function.The fingers of the interdigital capacitor preferably comprise at most two metal layers.

[0017] In each case, the second metal layer preferably extends over the entire length of the associated finger. In other words, this means that in each case the length of the finger in the region of the first metal layer can be the same as the length in the region of the second metal layer.

[0018] According to at least one embodiment, for each finger comprising a first metal layer and a second metal layer, the thickness of the associated first metal layer is less than the thickness of the associated second metal layer. For example, in each case, the thickness of the associated second metal layer is at least two times or at least five times or at least ten times greater than the thickness of the first metal layer. The thickness of the first metal layer is, for example, between 10 nm and 1 μm, preferably between 5 nm and 200 nm. In each case, the thickness of the first metal layer and the second metal layer is preferably constant within manufacturing tolerance limits. The thickness is measured perpendicular to the top side of the substrate.

[0019] The large thickness of the second metal layer results in a large mass loading which effectively suppresses oscillations and surface acoustic waves.

[0020] According to at least one embodiment, for all fingers comprising a first metal layer and a second metal layer, the associated second metal layer and the associated first metal layer are arranged identically to each other. This means that in each finger having a first metal layer and a second metal layer, the dimensions of the first metal layer and the second metal layer as well as the orientation and position of the second metal layer relative to the first metal layer are identical within manufacturing tolerance limits. Since the same mask can be used for the production of all fingers, such an interdigital capacitor can be produced very easily.

[0021] According to at least one embodiment, in different fingers, the associated second metal layer and the associated first metal layer are arranged differently relative to each other in a predetermined manner. This means, for example, that the position and / or orientation of the second metal layer relative to the first metal layer is different for different fingers. The dimensions of the first metal layer and the second metal layer may be the same for all fingers.

[0022] In this embodiment, the mass loading of the fingers is aperiodic along a direction perpendicular to the main extension direction of the fingers, which dampens oscillations and surface acoustic waves more effectively.

[0023] According to at least one embodiment, the electronic component further comprises a surface acoustic wave resonator (SAW resonator) having an interdigital transducer, wherein the interdigital transducer comprises two electrodes, each electrode having a plurality of fingers. Specifically, the electronic component is a surface acoustic wave filter (SAW filter). For example, the electronic component is a radio frequency filter particularly suitable for mobile communication systems (such as, smart phones). The electronic component is configured, for example, for Tx applications. Preferably, the electronic component comprises a plurality of SAW resonators as defined above or below.

[0024] The interdigital transducer can be designed similarly to the interdigital capacitor. Specifically, the fingers of the electrode are also arranged in a comb-like manner and cross-linked. The fingers of the interdigital transducer preferably all have the same size within the limits of manufacturing tolerances.

[0025] However, in contrast to an interdigital capacitor, an interdigital transducer should oscillate during normal operation and should therefore generate surface acoustic waves. Therefore, the fingers of the interdigital transducer preferably each have a constant width within the limits of manufacturing tolerances. In particular, the fingers of the interdigital transducer preferably include only the first metal layer and not the second metal layer.

[0026] The SAW resonator may also include a reflective structure between which the interdigital transducer is arranged. The reflective structure helps to confine the acoustic energy in the SAW resonator. The reflective structure prevents the acoustic energy from leaving the acoustic wave of the resonator along the direction of propagation of the acoustic wave. In addition, the reflective structure may be arranged near the electrodes of the interdigital transducer and connected to the ground potential.

[0027] The piezoelectric substrate may be a carrier for an electronic component. The piezoelectric substrate may also be a piezoelectric layer and the SAW resonator is a TF-SAW resonator (TF-SAW=Thin Film-Surface-Acoustic Wave). A TF-SAW resonator is characterized in that the piezoelectric material is not provided as a bulk material as in the case of a conventional SAW resonator, but rather as a thin film. The thin film material is characterized in that it is provided using wafer bonding or thin film material deposition techniques (e.g. sputtering, physical vapor deposition, chemical vapor deposition, molecular beam epitaxy, etc.).

[0028] According to at least one embodiment, the interdigital transducer is arranged on top of the piezoelectric substrate. This means that the interdigital transducer and the interdigital capacitor are arranged on the same piezoelectric substrate, preferably on the same top side of the piezoelectric substrate. The piezoelectric substrate is preferably continuous and / or integrally formed.

[0029] According to at least one embodiment, the interdigital transducer is electrically connected to the interdigital capacitor.For example, a conductor track on top of the piezoelectric substrate electrically connects the interdigital transducer and the interdigital capacitor.

[0030] According to at least one embodiment, the pitch between two adjacent fingers of the interdigital capacitor is greater than the pitch between two adjacent fingers of the interdigital transducer. Specifically, the pitch between two adjacent fingers of the interdigital capacitor is at least twice, at least five times, at least ten times, or at least 20 times the pitch between two adjacent fingers of the interdigital transducer. Additionally or alternatively, the pitch between two fingers of the interdigital capacitor is at most 100 times, at most 60 times, or at most 50 times greater than the pitch between two fingers of the interdigital transducer. For example, the pitch between two adjacent fingers of the interdigital transducer is at most 1 μm, at most 0.5 μm, and / or at least 0.1 μm, or at least 0.3 μm. The pitch between two adjacent fingers of the interdigital capacitor is, for example, at least 10 μm, at least 15 μm, and / or at most 50 μm, or at most 20 μm.

[0031] In each case, the pitch between two adjacent fingers of an interdigital capacitor / interdigital transducer is the distance between the centers (such as the centers of gravity or centers of symmetry) of the two adjacent fingers. The two adjacent fingers are typically fingers of different electrodes.

[0032] According to at least one embodiment, the width of the fingers of the interdigital capacitor is at least as large as the width of the fingers of the interdigital transducer. Here, in each case, the width of the fingers of the interdigital capacitor refers to the width of the associated first metal layer. For example, the width of the fingers of the interdigital capacitor is at least twice or at least five times or at least ten times or at least 20 times the width of the fingers of the interdigital transducer.

[0033] In SAW filters, interdigital capacitors are typically used that have a smaller pitch than the interdigital transducers of the SAW resonator. If the interdigital capacitors have a larger pitch, unwanted acoustic waves above the main resonance of the SAW resonator are typically generated, thereby reducing the filter performance. However, for the present invention as follows, in which a second metal layer is used for at least some of the fingers of the interdigital capacitor, the pitch between the fingers of the interdigital capacitor can be selected to be larger than the pitch of the interdigital transducer. Due to the second metal layer, the surface acoustic waves are suppressed by the additional mass loading.

[0034] This is particularly advantageous if the main frequency of the SAW resonator is above 3 GHz, since in this case the pitch of the interdigital transducer is already very small. Without the second metal layer, the pitch of the fingers of the interdigital capacitor will be even smaller. Therefore, the size of the fingers of the interdigital capacitor will be chosen to be very small, close to the process limits of current manufacturing technology. However, even if such a small pitch and such small sizes could be achieved, interdigital capacitors would not be feasible for most applications, since the capacitance fluctuations due to process variations would be prohibitive (variations > ±10%). Furthermore, the power handling capability of such capacitors is also very limited and is not suitable for, for example, Tx applications.

[0035] Since the fingers of the interdigital capacitors of the present invention can be chosen to be larger, they are almost immune to process variations, thereby providing stable capacitance values. In addition, they are able to handle a lot of power.

[0036] According to at least one embodiment, the fingers of the interdigital capacitor extend transversely, preferably perpendicularly, to the fingers of the interdigital transducer. This means that the main extension direction of the fingers of the interdigital capacitor is oriented transversely or perpendicularly to the main extension direction of the fingers of the interdigital transducer. In particular, the fingers of the interdigital capacitor are parallel or substantially parallel to the main propagation direction of the main mode of the SAW resonator.

[0037] Furthermore, by rotating the fingers of the interdigital transducer relative to the fingers of the interdigital capacitor, acoustic wave excitation due to the interdigital capacitor may be reduced.

[0038] In accordance with at least one embodiment, the surface acoustic wave resonator has a resonance frequency of at least 3 GHz (eg, between 3 GHz and 6 GHz or at least 6 GHz).

[0039] According to at least one embodiment, the fingers of the interdigital transducer have the same thickness as the first metal layer. "Same thickness" means having the same thickness within the limits of manufacturing tolerances. Preferably, the fingers of the interdigital transducer are made of the same material as the first metal layer. For example, the fingers of the interdigital capacitor and the first metal layer of the fingers of the interdigital transducer are produced in a common production process. For example, they are produced in a common sputtering or layer deposition or etching or photolithography process.

[0040] In accordance with at least one embodiment, the capacitance of the interdigital capacitor is at most 2 pF or at most 1 pF.

[0041] In accordance with at least one embodiment, each finger of an interdigital capacitor includes a first metal layer and a second metal layer.

[0042] In accordance with at least one embodiment, the electronic component is a surface acoustic wave filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In the following, electronic components are described by exemplary embodiments and with reference to the accompanying drawings. Here, the same reference numerals indicate the same elements in the drawings. However, the dimensions involved are not to scale. For better understanding, individual elements may be illustrated with exaggerated dimensions.

[0044] Figure 1A A first exemplary embodiment of an electronic assembly is shown in top view;

[0045] Figure 1B Shows Figure 1A Section along line AA';

[0046] Figure 2 A second exemplary embodiment of an electronic assembly is shown in cross-section;

[0047] Figure 3 A third exemplary embodiment of an electronic assembly is shown in top view;

[0048] FIG. 4A to FIG. 4C Performance measurements of exemplary embodiments of electronic assemblies are shown. DETAILED DESCRIPTION

[0049] Figure 1A A first exemplary embodiment of an electronic component is shown. The electronic component comprises a piezoelectric substrate 1 having a top side. Fig. 1 is a top view onto the top side of the piezoelectric substrate 1. The piezoelectric substrate 1 is, for example, a lithium tantalate substrate.

[0050] The interdigital capacitor 2 is arranged on the top side of the piezoelectric substrate 1. The interdigital capacitor 2 comprises a first electrode 21 and a second electrode 22. Both electrodes 21, 22 comprise a plurality of fingers 23. The fingers 23 of each electrode 21, 22 are arranged in a comb-like manner and are electrically connected to each other via busbars extending transversely to the fingers 23. The fingers 23 of the two electrodes 21, 22 cross each other and are electrically isolated from each other. The main extension directions of the fingers 23 are parallel to each other or substantially parallel to each other. In each case, the length of the finger 23 measured parallel to the main extension direction is greater than the width of the finger 23 measured perpendicular to the main extension direction. Both the length and the width are measured parallel to the top side of the piezoelectric substrate 1.

[0051] In addition, from Figure 1AAs can be seen in FIG. 1 , the fingers 23 each comprise a first metal layer 231 and a second metal layer 232. The first metal layer 231 is located between the second metal layer 232 and the piezoelectric substrate 1. The width of the finger 23 in the region of the second metal layer 232 is in each case constant within the limits of manufacturing tolerances. The same is true for the width in the region of the first metal layer 231. The width of the finger 23 in the region of the second metal layer 232 is smaller than the width in the region of the first metal layer 231.

[0052] The first metal layer 231 and the second metal layer 232 are formed of, for example, different materials. For example, the first metal layer 231 is Ti, and the second metal layer is Cu. However, the two metal layers 231 and 232 may also be formed of the same material.

[0053] Figure 1B Shows Figure 1A Cross-sectional view along line AA'. For simplicity, only a part of an electronic component with three fingers 23 is shown. It is clear again that in each finger 23, the width W1 of the finger 23 in the area of ​​the first metal layer 231 is greater than the width W2 of the finger 23 in the area of ​​the second metal layer 232. For example, the width W1 in the area of ​​the first metal layer 231 is three times the width W2 in the area of ​​the second metal layer 232. For example, the width in the area of ​​the first metal layer 231 is about 10 μm.

[0054] The thickness T2 of the second metal layer 232 measured perpendicular to the top side of the piezoelectric substrate 1 is greater than the thickness T1 of the first metal layer 231. For example, the thickness T2 of the second metal layer 232 is about ten times the thickness T1 of the first metal layer 231. The thickness T1 of the first metal layer is, for example, about 100 nm.

[0055] The pitch P2 between two adjacent fingers 23 is, for example, at least 10 μm. The capacitance of the interdigital capacitor 2 is preferably less than 1 pF.

[0056] With the interdigital capacitor shown in FIG1 , the surface acoustic waves that occur when the electrodes 21, 22 are excited with an alternating voltage are reduced. Specifically, this is due to the additional mass load brought by the second metal layer 232, which suppresses the oscillation of the finger 23. Therefore, this interdigital capacitor 2 is particularly suitable for electronic components in the form of electronic filters.

[0057] exist Figure 1B , the second metal layer 232 of the finger 23 always has the same size. The same is true for the first metal layer 231. In addition, the first metal layer 231 and the second metal layer 232 are always arranged in the same way relative to each other. Therefore, when going along a direction perpendicular to the main extension direction of the finger 23, the structure of the finger 23 is repeated periodically.

[0058] exist Figure 2 A second exemplary embodiment of an electronic assembly that is almost identical to the electronic assembly of FIG. 1 is shown in FIG. Figure 2 , the first metal layer 231 and the second metal layer 232 are arranged differently in different fingers 23. The first metal layer 231 of the finger 23 is periodically arranged along a direction perpendicular to the main extension direction of the finger 23. However, the second metal layer 232 is arranged at different positions in different fingers 23. In the leftmost finger 23, the metal layer 232 is shifted to the left side of the first metal layer 231. In the next finger 23, the second metal layer 232 is arranged in the center of the first metal layer 231. One finger 23 further to the right, the second metal layer 232 is shifted to the right side of the first metal layer 231.

[0059] The structure of the fingers 23 therefore has no periodicity when proceeding in a direction perpendicular to the main extension direction of the fingers 23. In this case, the excitation of surface acoustic waves is even further suppressed.

[0060] Figure 3 A third exemplary embodiment of an electronic component is shown in a top view on the top side of a piezoelectric substrate 1. The electronic component again comprises an interdigital capacitor 2 which is designed substantially similarly to the interdigital capacitor of FIG. 1. Figure 3 Only the number of fingers 23 is reduced.

[0061] In addition, Figure 3 In the embodiment, the electronic component includes a surface acoustic wave (SAW) resonator 3. The SAW resonator 3 includes an interdigital transducer 30 having a first electrode 31 and a second electrode 32, each electrode having a plurality of fingers 33. In addition, the fingers 33 of different electrodes 31, 32 cross each other and extend substantially parallel. The interdigital transducer 30 is disposed on the same piezoelectric substrate 1 as the interdigital capacitor 2.

[0062] The first electrode 31 is electrically connected to the input terminal 5 and the output terminal 7 via the conductor track 4. The second electrode 32 is connected to the ground terminal 8. When an alternating voltage is applied to the input terminal 5 so that the electrodes 31, 32 are at different potentials, surface acoustic waves are generated in the piezoelectric substrate 1 within the SAW resonator 3. These surface acoustic waves propagate in a direction perpendicular to the main extension direction of the fingers 33. If the pitch P3 of the fingers 33 corresponds to half the wavelength of the surface acoustic wave, the SAW resonator 3 operates in resonance. By tapping the voltage using the output terminal 7, a frequency filter is realized. Specifically, Figure 3 An electronic component of the present invention is a surface acoustic wave (SAW) filter, for example a radio frequency filter, such as a filter used in mobile communication equipment.

[0063] Figure 3 The resonance frequency of the SAW resonator 3 is, for example, greater than 3 GHz. In this case, the pitch P3 is, for example, between 0.3 μm and 0.5 μm.

[0064] exist Figure 3 In FIG. 1 , the interdigital capacitor 2 is electrically connected in parallel with the surface acoustic wave resonator 3. To this end, the second electrode 22 of the interdigital capacitor 2 is connected to the first electrode 31 of the interdigital transducer 30. The first electrode 21 of the interdigital capacitor 2 is connected to the ground terminal 6.

[0065] from Figure 3 It can be seen that the pitch P2 between two adjacent fingers 23 of the interdigital capacitor 2 is greater than the pitch P3 between adjacent fingers 33 of the interdigital transducer 30. Usually, one would avoid such a configuration, since the interdigital capacitor 2 would then also likely generate surface acoustic waves above the main resonance frequency, thereby degrading the filter performance of the electronic component. Therefore, usually, the pitch P2 in the interdigital capacitor 2 is selected to be smaller than the pitch P3 in the interdigital transducer 30. However, in the present case, this would be very difficult to achieve, since this would require a pitch P2 of less than 0.3 μm.

[0066] Here, an alternative method is proposed, in which the fingers 23 of the interdigital capacitor 2 each include a first metal layer 231 and a second metal layer 232. Figure 2 As described, the width of the finger 23 in the region of the first metal layer 231 is smaller than the width in the region of the second metal layer 232. Therefore, the generation of surface acoustic waves is suppressed. Therefore, the pitch P2 between adjacent fingers 23 can even be selected to be larger than the pitch P3 between adjacent fingers 33, which makes production easier. The interdigital capacitor 2 is very robust and almost insensitive to process variations. In addition, due to the second metal layer 232, the ohmic losses of the interdigital capacitor 2 are reduced, which further improves the quality factor Q of the interdigital capacitor 2.

[0067] In addition, Figure 3 In this case, the suppression of surface acoustic waves is achieved by rotating the fingers 23 of the interdigital capacitor 2 relative to the fingers 33 of the interdigital transducer 30. Specifically, the fingers 23 of the interdigital capacitor 2 extend substantially parallel to the propagation direction of the acoustic waves generated in the SAW resonator 3.

[0068] from Figure 3It can also be seen that the fingers 33 of the interdigital transducer 30 comprise only the first metal layer 231 and no second metal layer 232. However, the electrodes 21, 22, 31, 32 and the conductor track 4 each comprise both the first metal layer 231 and the second metal layer 232. In these elements, the first metal layer 231 and the second metal layer 232 may even have the same width. The conductor track 4 and the second metal layer 232 of the electrodes 21, 22, 31, 32 may be manufactured simultaneously with the second metal layer 232 of the fingers 23, for example in a common manufacturing step.

[0069] FIG. 4A to FIG. 4C Comparative measurement results of an ideal capacitor (dashed line), an interdigital capacitor with only a first metal layer on a piezoelectric substrate (short dashed line), and an interdigital capacitor according to the present invention with two metal layers on a piezoelectric substrate (solid line) are shown.

[0070] exist Figure 4A , the measurement results of reflectivity are shown. The y-axis represents the reflectivity, and the x-axis represents the frequency of the applied voltage in GHz.

[0071] exist Figure 4B , the capacitance is shown on the y-axis in pF, while the x-axis again represents the applied voltage frequency in GHz.

[0072] exist Figure 4C In , the y-axis shows the phase in degrees, and the x-axis again shows the applied voltage frequency in GHz.

[0073] As can be seen from all three figures, the interdigital capacitor of the present invention behaves almost like an ideal capacitor over the entire frequency range. However, the interdigital capacitor with only one metal layer will run away at certain frequencies.

[0074] The invention described herein is not limited by the description in conjunction with the exemplary embodiments. On the contrary, the invention includes any novel feature and any combination of features, in particular including any combination of features in the patent claims, even if the feature or the combination itself is not explicitly stated in the patent claims or the exemplary embodiments.

[0075] Reference numerals list

[0076] 1 Piezoelectric substrate

[0077] 2 Interdigital capacitors

[0078] 3 Surface Acoustic Wave Resonator

[0079] 4 Conductive track

[0080] 5 Input Terminals

[0081] 6 Ground terminal

[0082] 7 Output Terminals

[0083] 8 Ground terminal

[0084] 21 The first electrode of the interdigital capacitor

[0085] 22 The second electrode of the interdigital capacitor

[0086] 23 Fingers of interdigital capacitors

[0087] 30 Interdigital transducer

[0088] 31 The first electrode of the interdigital transducer

[0089] 32 The second electrode of the interdigital transducer

[0090] 33 Fingers of interdigital transducer

[0091] 231 First Metal Layer

[0092] 232 Second Metal Layer

[0093] P2 The pitch between fingers 23

[0094] P3 The pitch between fingers 33

[0095] T1 Thickness of the first metal layer

[0096] T2 The thickness of the second metal layer

[0097] W1 Width of the first metal layer

[0098] W2 Width of the second metal layer

Claims

1. An electronic component, include: Piezoelectric substrate (l); An interdigital capacitor (2) on top of the piezoelectric substrate (1); in The interdigital capacitor (2) comprises two electrodes (21, 22), each of the two electrodes (21, 22) comprises a plurality of fingers (23), Each finger of the plurality of fingers (23) comprises an associated first metal layer (231); At least some of the plurality of fingers (23) include an associated second metal layer (232) on top of the first metal layer (231); For each finger (23) comprising a first metal layer (231) and a second metal layer (232), a width (W1) of the finger (23) in the region of the associated first metal layer (231) is greater than a width (W2) of the finger (23) in the region of the associated second metal layer (232), Wherein in different fingers (23), the associated second metal layer (232) and the associated first metal layer (231) are arranged differently relative to each other.

2. The electronic component according to claim 1, wherein for each finger (23) comprising a first metal layer (231) and a second metal layer (232), a thickness (T1) of the associated first metal layer (231) is less than a thickness (T2) of the associated second metal layer (232).

3. The electronic component according to claim 1, wherein The electronic component also includes a surface acoustic wave resonator (3) having an interdigital transducer (30), wherein the interdigital transducer (30) includes two electrodes (31, 32), each having a plurality of fingers (33), The interdigital transducer (30) is arranged on top of the piezoelectric substrate (1), the interdigital transducer (30) being electrically connected to the interdigital capacitor (2).

4. The electronic component according to claim 3, wherein a pitch (P2) between two adjacent fingers (23) of the interdigital capacitor (2) is greater than a pitch (P3) between two adjacent fingers (33) of the interdigital transducer (30).

5. The electronic component according to claim 3 or 4, wherein the width of the plurality of fingers (23) of the interdigital capacitor (2) is at least as large as the width of the plurality of fingers (33) of the interdigital transducer (30).

6. The electronic assembly of claim 5, wherein the plurality of fingers (23) of the interdigital capacitor (2) extend transversely to the plurality of fingers (33) of the interdigital transducer (30).

7. The electronic component according to any one of claims 3-4 and 6, wherein the surface acoustic wave resonator (3) has a resonance frequency of at least 3 GHz.

8. The electronic component of claim 7, wherein the plurality of fingers (33) of the interdigital transducer (30) have the same thickness as the first metal layer (231).

9. The electronic component according to any one of claims 1-2, 3-4, 6 and 8, wherein the capacitance of the interdigital capacitor (2) is at most 2 pF.

10. The electronic component of claim 1, wherein each finger of the plurality of fingers (23) of the interdigital capacitor (2) comprises a first metal layer (231) and a second metal layer (232).

11. The electronic component of claim 1, wherein the electronic component is a surface acoustic wave filter.

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