CN113411069A - Bulk acoustic wave filter device and method for improving out-of-band rejection - Google Patents
Bulk acoustic wave filter device and method for improving out-of-band rejection Download PDFInfo
- Publication number
- CN113411069A CN113411069A CN202110619580.2A CN202110619580A CN113411069A CN 113411069 A CN113411069 A CN 113411069A CN 202110619580 A CN202110619580 A CN 202110619580A CN 113411069 A CN113411069 A CN 113411069A
- Authority
- CN
- China
- Prior art keywords
- bulk acoustic
- acoustic wave
- wave filter
- filter
- arm
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 12
- 229910052751 metal Inorganic materials 0.000 claims abstract description 72
- 239000002184 metal Substances 0.000 claims abstract description 72
- 239000000758 substrate Substances 0.000 claims abstract description 43
- 239000010409 thin film Substances 0.000 claims abstract description 25
- 238000007789 sealing Methods 0.000 claims abstract description 21
- 230000001681 protective effect Effects 0.000 claims abstract description 14
- 230000003071 parasitic effect Effects 0.000 claims description 26
- 230000001629 suppression Effects 0.000 claims description 12
- 239000010408 film Substances 0.000 claims description 8
- 230000008878 coupling Effects 0.000 claims description 6
- 238000010168 coupling process Methods 0.000 claims description 6
- 238000005859 coupling reaction Methods 0.000 claims description 6
- 239000003990 capacitor Substances 0.000 claims description 5
- 238000004806 packaging method and process Methods 0.000 claims description 2
- 238000003780 insertion Methods 0.000 abstract description 8
- 230000037431 insertion Effects 0.000 abstract description 8
- 238000013461 design Methods 0.000 abstract description 3
- 230000006866 deterioration Effects 0.000 abstract description 3
- 230000009286 beneficial effect Effects 0.000 abstract description 2
- 239000010410 layer Substances 0.000 description 20
- 230000000052 comparative effect Effects 0.000 description 9
- 230000005540 biological transmission Effects 0.000 description 7
- 238000011056 performance test Methods 0.000 description 7
- 238000004891 communication Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- 239000013078 crystal Substances 0.000 description 3
- 230000002411 adverse Effects 0.000 description 2
- 238000002955 isolation Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000011241 protective layer Substances 0.000 description 2
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- PMHQVHHXPFUNSP-UHFFFAOYSA-M copper(1+);methylsulfanylmethane;bromide Chemical compound Br[Cu].CSC PMHQVHHXPFUNSP-UHFFFAOYSA-M 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000010295 mobile communication Methods 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/46—Filters
- H03H9/54—Filters comprising resonators of piezo-electric or electrostrictive material
- H03H9/56—Monolithic crystal filters
- H03H9/564—Monolithic crystal filters implemented with thin-film techniques
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/02—Details
- H03H9/02007—Details of bulk acoustic wave devices
- H03H9/02086—Means for compensation or elimination of undesirable effects
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/02—Details
- H03H9/05—Holders; Supports
- H03H9/10—Mounting in enclosures
- H03H9/1007—Mounting in enclosures for bulk acoustic wave [BAW] devices
- H03H9/1014—Mounting in enclosures for bulk acoustic wave [BAW] devices the enclosure being defined by a frame built on a substrate and a cap, the frame having no mechanical contact with the BAW device
- H03H9/1021—Mounting in enclosures for bulk acoustic wave [BAW] devices the enclosure being defined by a frame built on a substrate and a cap, the frame having no mechanical contact with the BAW device the BAW device being of the cantilever type
Abstract
The invention discloses a bulk acoustic wave filter device and a method for improving out-of-band rejection, wherein the bulk acoustic wave filter device comprises a substrate, a protective cap wafer and a filter wafer, wherein a thin film bulk acoustic wave filter is arranged on the filter wafer, a metal sealing ring is formed on the periphery of the thin film bulk acoustic wave filter, and the metal sealing ring is connected with a ground plane of the substrate in a flip-chip bonding mode through a metalized through hole of the protective cap wafer. Furthermore, the parallel resonance arm in the filter is correspondingly connected with an inductor on the metal layer and then connected with the grounding metal, and the two adjacent inductors are separated by the grounding metal. The bulk acoustic wave filter and the method for improving the out-of-band rejection improve the out-of-band rejection of the filter under the condition of not increasing the filter level and the structure complexity, do not cause the deterioration of the insertion loss of the filter, and are more beneficial to the design of miniaturization of the filter.
Description
Technical Field
The invention relates to the technical field of microwave communication, in particular to a bulk acoustic wave filter device and a method for improving out-of-band rejection of the bulk acoustic wave filter.
Background
With the rapid development of mobile communication technology, a large number of radio frequency filters are required on a mobile phone terminal, and are mainly used for filtering out unwanted radio frequency signals, improving communication quality and improving user experience. Along with the expansion of services, the communication system has higher requirements on the performance of the filter and the volume size of the filter, and the bulk acoustic wave filter can just meet the requirements. The bulk acoustic wave filter generates resonance using the piezoelectric effect of the piezoelectric crystal. Since its resonance is generated by a mechanical wave (bulk acoustic wave), rather than an electromagnetic wave as a resonance source, the wavelength of the mechanical wave is much shorter than that of the electromagnetic wave. Therefore, the bulk acoustic wave resonator and the filter formed by the bulk acoustic wave resonator are greatly reduced in size compared with the conventional electromagnetic filter. On the other hand, since the crystal growth of the piezoelectric crystal can be well controlled at present, the loss of the resonator is extremely small, the quality factor is high, and the complicated design requirements such as a steep transition zone, low insertion loss and the like can be met. Due to the characteristics of small size, high roll-off, low insertion loss and the like of the bulk acoustic wave filter, the filter taking the bulk acoustic wave filter as the core is widely applied to communication systems. At present, communication systems develop towards multiple frequency bands, multiple systems and multiple modes, the used frequency bands are more and more intensive, in order to improve communication quality and reduce interference between the frequency bands, higher requirements are necessarily provided for out-of-band rejection of filters, and generally, the number of stages of the filters is increased to improve the out-of-band rejection.
Disclosure of Invention
The present invention provides a bulk acoustic wave filter capable of improving out-of-band rejection and a method for improving out-of-band rejection, so as to solve the above technical problems.
One aspect of the present invention provides a bulk acoustic wave filter device, which includes a substrate, a protective cap wafer, and a filter wafer, wherein a thin film bulk acoustic wave filter is disposed on the filter wafer, a metal sealing ring is formed on the periphery of the thin film bulk acoustic wave filter, and the metal sealing ring is connected to a ground plane of the substrate by flip-chip bonding through a metalized via hole of the protective cap wafer.
Preferably, the metal seal ring is formed by metal bonding the filter wafer and the protective cap wafer through wafer level packaging.
Preferably, the width of the metal sealing ring is less than or equal to 20 um.
Preferably, the thin film bulk acoustic filter includes a signal input port, a signal output port, and a plurality of series resonance arms connected between the signal input port and the signal output port, parallel resonance arms are connected between the signal input port and the series resonance arms, between two adjacent series resonance arms, and between the signal output port and the series resonance arms, and each of the series resonance arms and the parallel resonance arms includes at least one thin film bulk acoustic resonator; one end of the parallel resonance arm is electrically connected with the substrate in a flip-chip bonding mode through the metalized through hole of the protective cap wafer.
Preferably, the substrate is a multilayer substrate, the parallel resonant arms are connected to one metal layer of the substrate, each parallel resonant arm is connected to one inductor on the metal layer correspondingly and then connected to ground, and two adjacent inductors are separated by a grounding metal.
Preferably, the bulk acoustic wave filter includes series-connected resonator arms S1-S4 connected in series, one end of the series-connected resonator arm S1 is connected to the signal input port, one end of the series-connected resonator arm S4 is connected to the signal output port, and each of the series-connected resonator arms S1 and S2 includes 2 thin film bulk acoustic wave resonators;
the parallel resonant arm P1-P4 is further included, one end of the parallel resonant arm P1 is connected between the signal input end and the series resonant arm S1, one end of the parallel resonant arm P2 is connected between the series resonant arms S1 and S2, one end of the parallel resonant arm P3 is connected between the series resonant arms S2 and S3, and one end of the parallel resonant arm P4 is connected between the series resonant arms S3 and S4; the other end of the parallel resonant arm P1 is grounded via an inductor L1, the other end of the parallel resonant arm P2 is grounded via an inductor L2, the other end of the parallel resonant arm P3 is grounded via an inductor L3, and the other end of the parallel resonant arm P4 is grounded via an inductor L4.
Another aspect of the present invention is to provide a method for improving out-of-band rejection of a bulk acoustic wave filter, where the bulk acoustic wave filter includes a substrate and a thin film bulk acoustic wave filter, and a metal seal ring is formed on the periphery of the thin film bulk acoustic wave filter;
connecting the metal sealing ring with a ground plane of the substrate, and introducing a parasitic inductor to enable the parasitic inductor and a parasitic capacitor between the metal sealing ring and a resonator of the film bulk acoustic wave filter to form a resonant circuit so as to improve the suppression of the right side of a pass band of the filter;
the grounding end of a resonator forming the film bulk acoustic wave filter is connected with the grounding inductor of the metal layer of the substrate and then grounded, and grounding metal is arranged between two adjacent grounding inductors to reduce mutual coupling between the grounding inductors so as to improve the suppression of the left side of the passband of the filter.
Preferably, the inductance of said parasitic inductance is adjusted, thereby adjusting the suppression level on the right side of the filter passband.
The invention has at least the following technical effects:
the bulk acoustic wave filter and the method for improving the out-of-band rejection improve the out-of-band rejection of the filter under the condition of not increasing the filter level and the structure complexity, do not cause the deterioration of the insertion loss of the filter, and are more beneficial to the design of miniaturization of the filter.
Drawings
Fig. 1 is a schematic structural diagram of a bulk acoustic wave filter according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of a package of a bulk acoustic wave filter according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of an equivalent circuit of a bulk acoustic wave filter according to an embodiment of the present invention;
fig. 4 is a schematic diagram of an inductor layout structure of a metal layer of a substrate according to an embodiment of the invention;
FIG. 5 is a graph of a pass band performance test of an embodiment of the present invention and a comparative example;
FIG. 6 is a pass band performance test curve for different seal ring width settings in an embodiment of the present invention;
FIG. 7 is a pass band performance test curve of another embodiment of the present invention and a comparative example.
Reference numerals:
the structure comprises a 1-filter wafer, a 2-metal sealing ring, a 3-protective cap wafer, a 4-metalized through hole, a 5-thin film bulk acoustic resonator, a 6-bonding pad, a 7-gold ball, an 8-substrate and a 9-grounding metal.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art.
The invention provides the following embodiments in conjunction with figures 1-7:
referring to fig. 1-2, the bulk acoustic wave filter device provided in this embodiment includes a substrate 8, a protective cap wafer 3, and a filter wafer 1, wherein a bulk acoustic wave filter is disposed on the filter wafer, a metal sealing ring 2 is formed on the periphery of the bulk acoustic wave filter, and the metal sealing ring 2 is connected to a ground plane of the substrate 8 by flip-chip bonding through a metalized via 4 of the protective cap wafer. It can be understood that, in the above-mentioned solution, the metal seal ring 2 forms a surrounding protection for the film bulk acoustic resonator 5 constituting the bulk acoustic wave filter to prevent gas, liquid and the like from polluting the filter, and in practical applications, in order to reduce the package size of the filter device, the metal seal ring is usually arranged as close as possible to the resonators, so that the space between each resonator and the metal seal ring is reduced. However, the applicant has found that when the distance between each resonator and the metal seal ring is reduced to a certain extent, the resonators and the metal seal ring are coupled with each other to generate parasitic capacitance at the input and output ends of the filter, so that the out-of-band rejection of the pass band of the filter is deteriorated to various extents. Based on this, the solution is proposed, a parasitic inductor is introduced by connecting the metal seal ring with the ground plane of the substrate, the parasitic inductor and the parasitic capacitor between the input and output ends of the filter can form a resonant circuit, and by adjusting the size of the parasitic inductor, resonance can be formed on the right side of the filter passband to suppress the adverse effect generated by the parasitic capacitor, thereby improving the suppression level on the right side of the filter passband. It will further be appreciated that the parasitic inductance can be adjusted by varying the cross-sectional width of the metal seal ring and/or by introducing additional inductance by way of routing in the corresponding metal layer in the multilayer substrate (i.e., the ground plane on the substrate to which the metal seal ring is connected), i.e., by adjusting the inductance of the routing and thus the parasitic inductance.
In a preferred embodiment, the metal seal ring is formed by metal bonding the filter wafer and the protective cap wafer by a Wafer Level Package (WLP). This ensures the sealing property of the metal seal ring against the filter and the structural stability.
As an alternative embodiment, the basic structure of the film bulk acoustic resonator comprises a substrate, the material of the substrate is high-resistance silicon, a bottom electrode is arranged on the upper surface of the substrate, and an air cavity for reflecting bulk acoustic wave energy is formed between the bottom electrode and the substrate; the piezoelectric layer is grown on the upper surface of the bottom electrode and the top electrode is grown on the upper surface of the piezoelectric layer. To further improve the reliability of the resonator, a protective layer is provided on the top surface of the top electrode. Preferably, the piezoelectric layer is made of aluminum nitride, the bottom electrode and the top electrode are made of molybdenum, and the protective layer is made of silicon nitride.
In some embodiments, the bulk acoustic wave filter comprises a signal input port (port1), a signal output port (port2), and a plurality of series resonator arms connected between the signal input port and the signal output port, parallel resonator arms connected between the signal input port and the series resonator arms, between two adjacent series resonator arms, and between the signal output port and the series resonator arms, each of the series resonator arms and the parallel resonator arms comprising at least one thin film bulk acoustic wave resonator; one end of the parallel resonance arm is electrically connected with the substrate in a flip-chip bonding mode through the metalized through hole of the protective cap wafer. As a specific embodiment, referring to fig. 3, the bulk acoustic wave filter includes series resonator arms S1-S4 connected in series, one end of the series resonator arm S1 is connected to the signal input port, and one end of the series resonator arm S4 is connected to the signal output port; the parallel resonant arm P1-P4 is provided, one end of the parallel resonant arm P1 is connected between a signal input end and the series resonant arm S1, one end of the parallel resonant arm P2 is connected between the series resonant arms S1 and S2, one end of the parallel resonant arm P3 is connected between the series resonant arms S2 and S3, and one end of the parallel resonant arm P4 is connected between the series resonant arms S3 and S4; the other end of the parallel resonant arm P1 is grounded via an inductor L1, the other end of the parallel resonant arm P2 is grounded via an inductor L2, the other end of the parallel resonant arm P3 is grounded via an inductor L3, and the other end of the parallel resonant arm P4 is grounded via an inductor L4. Alternatively, to increase the power of the bulk acoustic wave filter, the series resonator arm S1 includes thin film bulk acoustic resonators S1a and S1b, the series resonator arm S2 includes thin film bulk acoustic resonators S2a and S2b, the parallel resonator arm P1 includes thin film bulk acoustic resonators P1a and P1b, and the parallel resonator arm P2 includes thin film bulk acoustic resonators P2a and P2 b. The parallel resonance arms P1, P2, P3 and P4 of the filter can be loaded with mass loads, the parallel resonance frequency of the parallel resonance arms is close to the series resonance frequency of the series resonance arms S1, S2, S3 and S4, so that a band-pass filter is formed, the inductors L1, L2, L3 and L4 can play a role in controlling the transmission zero of the filter, and the out-of-band rejection of the filter is optimized. As shown in fig. 3, Cr1 and Cr2 are parasitic capacitances generated by coupling between the metal seal ring and the resonator, Lr is a parasitic inductance introduced by connecting the metal seal ring with the ground plane of the substrate, the parasitic inductance Lr and the parasitic capacitances (Cr1 and Cr2) can form a resonant circuit, and by adjusting the size of the parasitic inductance Lr, resonance can be formed on the right side of the filter passband to suppress adverse effects generated by the parasitic capacitances. Further, with the metal seal ring not grounded as comparative example 1, the performance test is performed on example 1 and comparative example 1, and fig. 5 shows the pass band performance test curve (transmission curve) of example 1 and comparative example 1, and it can be seen from the figure that example 1 improves the out-of-band rejection on the right side of the pass band of the filter by about 5dB compared with comparative example 1, and has almost no influence on the out-of-band rejection on the left side of the pass band of the filter and the insertion loss in the pass band.
In a preferred embodiment, the cross-sectional width of the metal seal ring is 20um or less. Fig. 6 is a performance curve of different metal seal ring section widths, and the solid line is a performance curve of the seal ring section width Wsr being 20 um; the dotted line is a performance curve of the sealing ring section width Wsr being 40 um; the long dashed line is the performance curve for a seal ring section width Wsr of 60 um. As can be seen from the figure, as the cross-sectional width Wsr of the seal ring increases, the out-of-band rejection of a portion of the band near the left side of the passband of the bulk acoustic wave filter becomes worse, while the out-of-band rejection on the right side of the passband of the filter and the insertion loss in the passband have almost no influence. The out-of-band suppression of Wsr ═ 20um is improved by about 6dB compared with Wsr ═ 60um, and therefore, under the condition of ensuring the package reliability, it is recommended to set the cross-sectional width of the metal seal ring as small as possible.
In a preferred embodiment, the substrate is a multilayer substrate formed by alternately stacking multiple metal layers and dielectric layers, the parallel resonant arms are connected to one metal layer of the substrate, each parallel resonant arm is connected to one inductor on the metal layer and then connected to ground, and two adjacent inductors are separated by a ground metal. Alternatively, referring to fig. 2, the multilayer substrate includes four metal layers M1, M2, M3 and M4, the metal seal ring 2 and the thin film bulk acoustic resonator 5 on the filter wafer are electrically connected to the corresponding pattern of the M1 layer of the multilayer substrate, the M2 and M3 layers are mainly used to provide the ground inductance of the parallel resonator arms, and the M4 layer is a distributed pin for connection to other devices. Specifically, referring to fig. 4, which is a schematic diagram of an inductor layout structure of one metal layer (M2 or M3) of a substrate, parallel resonant arms P1, P2, P3 and P4 are correspondingly connected with inductors L1, L2, L3 and L4, and two adjacent inductors are separated by a grounding metal 9. It should be noted that, in practical applications, an inductor is usually disposed between the parallel resonant arm and the ground in the parallel branch of the ladder structure, so as to adjust the position of the transmission zero point, so as to obtain better out-of-band rejection performance. The applicant has found that electromagnetic coupling is easily formed between the inductances in the parallel branches and can lead to a shift of the transmission zero, thereby causing a deterioration of the out-of-band rejection of the bulk acoustic wave filter. Based on this, the above solution is proposed, in this embodiment, the grounding metal 9 is disposed between the inductors of the substrate metal layers to reduce mutual coupling between the inductors, so that the position of the transmission zero is within the frequency band to be suppressed on the left side of the passband, and the out-of-band suppression on the left side of the passband of the bulk acoustic wave filter is further optimized. As a comparative example 2, no grounding metal is arranged between inductors of metal layers for isolation, and the performance test is carried out on the example 2 and the comparative example, referring to fig. 7, a passband performance test curve of the example 2 and the comparative example 2 is shown, and it can be seen from the figure that after the grounding metal is arranged between the inductors for isolation, the transmission zero point Z1 moves towards a high frequency direction, and the transmission zero points Z2 and Z3 slightly move towards a low frequency, so that the out-of-band rejection level of the left side of the filter passband, which needs to be rejected, is improved by about 5dB as a whole, and the out-of-band rejection on the right side of the filter passband and the insertion loss in the passband are hardly affected.
It will be appreciated that in the test curves of figures 5, 6 and 7, the ordinate IL represents the insertion loss.
The embodiment of the invention also provides a method for improving out-of-band rejection of the bulk acoustic wave filter, wherein the bulk acoustic wave filter comprises a substrate and a thin film bulk acoustic wave filter, and a metal sealing ring is formed at the periphery of the thin film bulk acoustic wave filter;
connecting the metal sealing ring with a ground plane of the substrate, and introducing a parasitic inductor to enable the parasitic inductor and a parasitic capacitor between the metal sealing ring and a resonator of the film bulk acoustic wave filter to form a resonant circuit so as to improve the suppression of the right side of a pass band of the filter;
the grounding end of a resonator forming the film bulk acoustic wave filter is connected with the grounding inductor of the metal layer of the substrate and then grounded, and grounding metal is arranged between two adjacent grounding inductors to reduce mutual coupling between the grounding inductors so as to improve the suppression of the left side of the passband of the filter.
Preferably, the inductance of said parasitic inductance is adjusted, thereby adjusting the suppression level on the right side of the filter passband.
In the description of the present invention, it is to be understood that the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, are merely for convenience of description of the present invention, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (8)
1. A bulk acoustic wave filter device is characterized by comprising a substrate, a protective cap wafer and a filter wafer, wherein a thin film bulk acoustic wave filter is arranged on the filter wafer, a metal sealing ring is formed on the periphery of the thin film bulk acoustic wave filter, and the metal sealing ring is connected with a ground plane of the substrate in a flip-chip bonding mode through a metalized through hole of the protective cap wafer.
2. The bulk acoustic wave filter device according to claim 1, characterized in that: the metal sealing ring is formed by metal bonding the filter wafer and the protective cap wafer through wafer level packaging.
3. The bulk acoustic wave filter device according to claim 1, characterized in that: the cross-sectional width of the metal sealing ring is less than or equal to 20 um.
4. The bulk acoustic wave filter device according to claim 1, characterized in that: the thin film bulk acoustic filter comprises a signal input port, a signal output port and a plurality of series resonance arms connected between the signal input port and the signal output port, parallel resonance arms are connected between the signal input end and the series resonance arms, between two adjacent series resonance arms and between the signal output end and the series resonance arms, and each series resonance arm and each parallel resonance arm comprises at least one thin film bulk acoustic resonator; one end of the parallel resonance arm is electrically connected with the substrate in a flip-chip bonding mode through the metalized through hole of the protective cap wafer.
5. The bulk acoustic wave filter device according to claim 4, characterized in that: the substrate is a multilayer substrate, the parallel resonance arms are connected to one metal layer of the substrate, each parallel resonance arm is correspondingly connected with one inductor on the metal layer and then connected to the ground, and two adjacent inductors are separated from each other through the ground metal.
6. The bulk acoustic wave filter device according to claim 4, characterized in that: the bulk acoustic wave filter comprises series resonance arms S1-S4 which are connected in sequence, one end of each series resonance arm S1 is connected with the signal input port, one end of each series resonance arm S4 is connected with the signal output port, and each series resonance arm S1 and S2 comprises 2 thin film bulk acoustic wave resonators;
the parallel resonant arm P1-P4 is further included, one end of the parallel resonant arm P1 is connected between the signal input end and the series resonant arm S1, one end of the parallel resonant arm P2 is connected between the series resonant arms S1 and S2, one end of the parallel resonant arm P3 is connected between the series resonant arms S2 and S3, and one end of the parallel resonant arm P4 is connected between the series resonant arms S3 and S4; the other end of the parallel resonant arm P1 is grounded via an inductor L1, the other end of the parallel resonant arm P2 is grounded via an inductor L2, the other end of the parallel resonant arm P3 is grounded via an inductor L3, and the other end of the parallel resonant arm P4 is grounded via an inductor L4.
7. A method for improving out-of-band rejection of a bulk acoustic wave filter, wherein the bulk acoustic wave filter comprises a substrate and a thin film bulk acoustic wave filter, and a metal seal ring is formed on the periphery of the thin film bulk acoustic wave filter, and the method is characterized in that:
connecting the metal sealing ring with a ground plane of the substrate, and introducing a parasitic inductor to enable the parasitic inductor and a parasitic capacitor between the metal sealing ring and a resonator of the film bulk acoustic wave filter to form a resonant circuit so as to improve the suppression of the right side of a pass band of the filter;
the grounding end of a resonator forming the film bulk acoustic wave filter is connected with the grounding inductor of the metal layer of the substrate and then grounded, and grounding metal is arranged between two adjacent grounding inductors to reduce mutual coupling between the grounding inductors so as to improve the suppression of the left side of the passband of the filter.
8. The method of claim 7, wherein the out-of-band rejection of the bulk acoustic wave filter is: and adjusting the inductance value of the parasitic inductance, thereby adjusting the suppression level on the right side of the filter passband.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110619580.2A CN113411069A (en) | 2021-06-03 | 2021-06-03 | Bulk acoustic wave filter device and method for improving out-of-band rejection |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110619580.2A CN113411069A (en) | 2021-06-03 | 2021-06-03 | Bulk acoustic wave filter device and method for improving out-of-band rejection |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113411069A true CN113411069A (en) | 2021-09-17 |
Family
ID=77676168
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110619580.2A Pending CN113411069A (en) | 2021-06-03 | 2021-06-03 | Bulk acoustic wave filter device and method for improving out-of-band rejection |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113411069A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114070221A (en) * | 2021-11-17 | 2022-02-18 | 安徽安努奇科技有限公司 | Filter circuit and electronic equipment |
| CN114465601A (en) * | 2022-04-13 | 2022-05-10 | 苏州汉天下电子有限公司 | Filter, duplexer and multiplexer |
| CN115549633A (en) * | 2022-10-27 | 2022-12-30 | 泓林微电子（昆山）有限公司 | Substrate integrated inductor shielding structure, acoustic wave filter device composed of substrate integrated inductor shielding structure and application of substrate integrated inductor shielding structure |
| CN117097298A (en) * | 2023-10-19 | 2023-11-21 | 苏州声芯电子科技有限公司 | Filter circuit for improving out-of-band rejection |
| CN117118390B (en) * | 2023-08-01 | 2024-02-13 | 无锡市好达电子股份有限公司 | elastic wave filter |
| EP4325722A3 (en) * | 2022-07-20 | 2024-04-03 | Suzhou HunterSun Electronics Co., Ltd. | Semiconductor device, communication apparatus, and producing method thereof |
Citations (24)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006100361A (en) * | 2004-09-28 | 2006-04-13 | Kyocera Corp | High-frequency module |
| JP2006142447A (en) * | 2004-11-22 | 2006-06-08 | Sony Corp | Functional element and its manufacturing method |
| JP2007266865A (en) * | 2006-03-28 | 2007-10-11 | Kyocera Corp | Surface acoustic wave device |
| CN101599750A (en) * | 2009-06-16 | 2009-12-09 | 常熟市华通电子有限公司 | Surface wave device encapsulation structure |
| US20120049978A1 (en) * | 2010-08-27 | 2012-03-01 | Wei Pang | Vertically integrated module in a wafer level package |
| KR101336150B1 (en) * | 2012-06-21 | 2013-12-03 | (주)와이솔 | Surface acoustic wave device and method of manufacturing the same |
| CN103943930A (en) * | 2014-05-13 | 2014-07-23 | 苏州博海创业微系统有限公司 | LTCC (low temperature co-fired ceramic) multi-path balance power divider |
| JP2014170809A (en) * | 2013-03-01 | 2014-09-18 | Sii Crystal Technology Inc | Resist application apparatus, resist application method and piezoelectric vibration piece |
| CN109728790A (en) * | 2019-01-16 | 2019-05-07 | 厦门云天半导体科技有限公司 | A kind of wafer level packaging structure and its technique of filter |
| CN109831176A (en) * | 2018-12-05 | 2019-05-31 | 天津大学 | A kind of piezoelectric acoustic-wave filter and duplexer |
| CN109861665A (en) * | 2018-12-14 | 2019-06-07 | 天津大学 | A kind of piezoelectric acoustic-wave filter |
| CN110022133A (en) * | 2019-04-24 | 2019-07-16 | 电子科技大学 | A kind of miniaturization inductive type variable band-pass filter and preparation method thereof |
| CN110492206A (en) * | 2019-08-09 | 2019-11-22 | 天津大学 | A kind of duplexer |
| CN110504942A (en) * | 2019-08-09 | 2019-11-26 | 天津大学 | A kind of bulk accoustic wave filter and electronic equipment |
| CN110729979A (en) * | 2019-09-30 | 2020-01-24 | 中国电子科技集团公司第二十六研究所 | Wafer-level packaging method and structure of film bulk acoustic wave filter |
| CN110971209A (en) * | 2019-11-04 | 2020-04-07 | 天津大学 | Method for improving power capacity of bulk acoustic wave filter and filter element |
| CN111010143A (en) * | 2019-11-20 | 2020-04-14 | 天津大学 | Bulk acoustic wave filter, method for manufacturing the same, and duplexer |
| CN111342812A (en) * | 2018-12-18 | 2020-06-26 | 天津大学 | Filter with phase-shifting network module at two ports, duplexer and electronic equipment with filter |
| CN111342814A (en) * | 2020-02-10 | 2020-06-26 | 诺思(天津)微系统有限责任公司 | Bulk acoustic wave filter, multiplexer and electronic equipment |
| CN111464147A (en) * | 2020-04-14 | 2020-07-28 | 诺思(天津)微系统有限责任公司 | Filter and method for improving power capacity thereof, multiplexer and communication equipment |
| CN111464148A (en) * | 2020-04-20 | 2020-07-28 | 诺思(天津)微系统有限责任公司 | Filter element, multiplexer, and communication device |
| CN111600565A (en) * | 2020-01-03 | 2020-08-28 | 诺思(天津)微系统有限责任公司 | Filter circuit, signal processing device and method for manufacturing filter circuit |
| CN112532201A (en) * | 2021-02-07 | 2021-03-19 | 成都频岢微电子有限公司 | Layout structure for improving out-of-band rejection of surface acoustic wave receiving filter |
| CN112671362A (en) * | 2020-11-27 | 2021-04-16 | 中国电子科技集团公司第十三研究所 | FBAR filter |
-
2021
- 2021-06-03 CN CN202110619580.2A patent/CN113411069A/en active Pending
Patent Citations (24)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006100361A (en) * | 2004-09-28 | 2006-04-13 | Kyocera Corp | High-frequency module |
| JP2006142447A (en) * | 2004-11-22 | 2006-06-08 | Sony Corp | Functional element and its manufacturing method |
| JP2007266865A (en) * | 2006-03-28 | 2007-10-11 | Kyocera Corp | Surface acoustic wave device |
| CN101599750A (en) * | 2009-06-16 | 2009-12-09 | 常熟市华通电子有限公司 | Surface wave device encapsulation structure |
| US20120049978A1 (en) * | 2010-08-27 | 2012-03-01 | Wei Pang | Vertically integrated module in a wafer level package |
| KR101336150B1 (en) * | 2012-06-21 | 2013-12-03 | (주)와이솔 | Surface acoustic wave device and method of manufacturing the same |
| JP2014170809A (en) * | 2013-03-01 | 2014-09-18 | Sii Crystal Technology Inc | Resist application apparatus, resist application method and piezoelectric vibration piece |
| CN103943930A (en) * | 2014-05-13 | 2014-07-23 | 苏州博海创业微系统有限公司 | LTCC (low temperature co-fired ceramic) multi-path balance power divider |
| CN109831176A (en) * | 2018-12-05 | 2019-05-31 | 天津大学 | A kind of piezoelectric acoustic-wave filter and duplexer |
| CN109861665A (en) * | 2018-12-14 | 2019-06-07 | 天津大学 | A kind of piezoelectric acoustic-wave filter |
| CN111342812A (en) * | 2018-12-18 | 2020-06-26 | 天津大学 | Filter with phase-shifting network module at two ports, duplexer and electronic equipment with filter |
| CN109728790A (en) * | 2019-01-16 | 2019-05-07 | 厦门云天半导体科技有限公司 | A kind of wafer level packaging structure and its technique of filter |
| CN110022133A (en) * | 2019-04-24 | 2019-07-16 | 电子科技大学 | A kind of miniaturization inductive type variable band-pass filter and preparation method thereof |
| CN110492206A (en) * | 2019-08-09 | 2019-11-22 | 天津大学 | A kind of duplexer |
| CN110504942A (en) * | 2019-08-09 | 2019-11-26 | 天津大学 | A kind of bulk accoustic wave filter and electronic equipment |
| CN110729979A (en) * | 2019-09-30 | 2020-01-24 | 中国电子科技集团公司第二十六研究所 | Wafer-level packaging method and structure of film bulk acoustic wave filter |
| CN110971209A (en) * | 2019-11-04 | 2020-04-07 | 天津大学 | Method for improving power capacity of bulk acoustic wave filter and filter element |
| CN111010143A (en) * | 2019-11-20 | 2020-04-14 | 天津大学 | Bulk acoustic wave filter, method for manufacturing the same, and duplexer |
| CN111600565A (en) * | 2020-01-03 | 2020-08-28 | 诺思(天津)微系统有限责任公司 | Filter circuit, signal processing device and method for manufacturing filter circuit |
| CN111342814A (en) * | 2020-02-10 | 2020-06-26 | 诺思(天津)微系统有限责任公司 | Bulk acoustic wave filter, multiplexer and electronic equipment |
| CN111464147A (en) * | 2020-04-14 | 2020-07-28 | 诺思(天津)微系统有限责任公司 | Filter and method for improving power capacity thereof, multiplexer and communication equipment |
| CN111464148A (en) * | 2020-04-20 | 2020-07-28 | 诺思(天津)微系统有限责任公司 | Filter element, multiplexer, and communication device |
| CN112671362A (en) * | 2020-11-27 | 2021-04-16 | 中国电子科技集团公司第十三研究所 | FBAR filter |
| CN112532201A (en) * | 2021-02-07 | 2021-03-19 | 成都频岢微电子有限公司 | Layout structure for improving out-of-band rejection of surface acoustic wave receiving filter |
Non-Patent Citations (3)
| Title |
|---|
| RICHARD SCHUHMANN: "Resonant acoustic measurement of vapor phase transport phenomenon in porous media", 《THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA》 * |
| 王萍: "《电子电气设备设计与制造技术》", 30 June 2018, 北京工业大学出版社 * |
| 顾聪聪: "具有温度补偿的薄膜体声波压力传感器及采集系统设计", 《中国优秀博硕士学位论文全文数据库(硕士)信息科技辑》 * |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114070221A (en) * | 2021-11-17 | 2022-02-18 | 安徽安努奇科技有限公司 | Filter circuit and electronic equipment |
| WO2023087606A1 (en) * | 2021-11-17 | 2023-05-25 | 安徽安努奇科技有限公司 | Filter circuit and electronic device |
| CN114465601A (en) * | 2022-04-13 | 2022-05-10 | 苏州汉天下电子有限公司 | Filter, duplexer and multiplexer |
| CN114465601B (en) * | 2022-04-13 | 2022-08-12 | 苏州汉天下电子有限公司 | Filter, duplexer and multiplexer |
| EP4325722A3 (en) * | 2022-07-20 | 2024-04-03 | Suzhou HunterSun Electronics Co., Ltd. | Semiconductor device, communication apparatus, and producing method thereof |
| CN115549633A (en) * | 2022-10-27 | 2022-12-30 | 泓林微电子（昆山）有限公司 | Substrate integrated inductor shielding structure, acoustic wave filter device composed of substrate integrated inductor shielding structure and application of substrate integrated inductor shielding structure |
| CN115549633B (en) * | 2022-10-27 | 2023-07-28 | 泓林微电子（昆山）有限公司 | Substrate integrated inductance shielding structure, acoustic wave filter device formed by same and application of acoustic wave filter device |
| CN117118390B (en) * | 2023-08-01 | 2024-02-13 | 无锡市好达电子股份有限公司 | elastic wave filter |
| CN117097298A (en) * | 2023-10-19 | 2023-11-21 | 苏州声芯电子科技有限公司 | Filter circuit for improving out-of-band rejection |
| CN117097298B (en) * | 2023-10-19 | 2024-02-09 | 苏州声芯电子科技有限公司 | Filter circuit for improving out-of-band rejection |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113411069A (en) | Bulk acoustic wave filter device and method for improving out-of-band rejection | |
| CN110492864B (en) | Packaging structure of bulk acoustic wave filter and manufacturing method of filter | |
| US7498899B2 (en) | Duplexer with filters including film bulk acoustic resonators | |
| KR101116941B1 (en) | Filter, duplexer and communication module | |
| EP1432133B1 (en) | Duplexer and communication apparatus | |
| US11050412B2 (en) | Acoustic filter using acoustic coupling | |
| US10581156B2 (en) | Compensation circuit to mitigate antenna-to-antenna coupling | |
| JP4819811B2 (en) | Filter device with two bulk wave resonators | |
| JP5757629B2 (en) | Filter, duplexer, communication module, communication device | |
| WO2020108527A1 (en) | Bulk acoustic resonator-based filter having dual functions of bandpass and highpass | |
| US7825748B2 (en) | Integrable tunable filter circuit comprising a set of BAW resonators | |
| EP1641119A2 (en) | Duplexer | |
| CN109713407B (en) | Ladder-shaped structure duplexer and method for improving isolation of duplexer | |
| CN111342793B (en) | Band-pass filter, method for improving suppression level thereof, duplexer and electronic device | |
| CN115395922A (en) | Bulk acoustic wave duplexer | |
| JP2010206375A (en) | Branching filter | |
| JP2011193080A (en) | Branching filter | |
| CN111342806B (en) | Piezoelectric filter having lamb wave resonator, duplexer, and electronic device | |
| EP2892151B1 (en) | Filter device and duplexer | |
| US8508316B2 (en) | Bulk acoustic wave filter of ladder-type structure | |
| CN114785317A (en) | Bulk acoustic wave duplexer | |
| CN111342789A (en) | Filter unit with coupling inductor, filter and electronic equipment | |
| JP7092239B2 (en) | Matching circuit and communication equipment | |
| US11923827B2 (en) | Bulk acoustic wave resonator stacked onto an integrated passive device | |
| JP5503764B2 (en) | Filters, duplexers, communication modules |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210917 |
|
| RJ01 | Rejection of invention patent application after publication |