Abstract: A method of manufacturing a bulk acoustic wave filter is provided, including: forming an acoustic reflection air cavity, a sacrificial layer, a seed layer, a lower electrode layer and a piezoelectric layer of n resonators on a substrate in sequence, wherein n is greater than or equal to 2; taking N from 1 to n for respectively repeating following steps: forming an N-th metal hard mask layer, defining an effective area of a first resonator to an N-th resonator by using a photolithography process, removing the N-th metal hard mask layer outside the effective area of the first resonator to the N-th resonator, oxidizing the piezoelectric layer outside the effective area of the first resonator to the N-th resonator to form an N-th oxidized part of the piezoelectric layer, and etching the N-th oxidized part of the piezoelectric layer; removing the metal hard mask layer of the effective area of the first resonator to the N-th resonator, so as to form the piezoelectric layer having different thicknesses of the first

Abstract: A chip encapsulation structure, including: a wafer provided with a groove; a first metal wire arranged on surfaces of the groove and the wafer; a metal solder ball arranged on the first metal wire or on a metal pad of the chip, and is configured to solder the metal pad of the chip to the first metal wire; a first plastic encapsulation film covering upper surfaces of the wafer, the chip and the first metal wire, and entering a gap between a periphery of a functional area of the chip and the first metal wire, so as to form a closed cavity among the wafer, the groove and the chip; an inductive structure arranged on an upper surface of the first plastic encapsulation film and/or a lower surface of the wafer, and connected to the chip through the first metal wire; and a pad arranged on the inductive structure.

Abstract: An acoustic wave device and a filter. The acoustic wave device comprises: a substrate, a lower electrode layer, a piezoelectric layer, and an upper electrode layer, which are sequentially stacked from bottom to top, where at least one air cavity is disposed in the substrate at a region corresponding to the upper electrode layer, and at least one of: a first hanging bridge is located at a portion of the upper electrode layer which connects to outside, first hanging roofs are located at an edge and an inner portion of the upper electrode layer, and at least one via hole runs through one of the first hanging roofs which is located at the inner portion of the upper electrode layer; a quantity of the at least one air cavity is greater than one; or the upper electrode layer has a recess extending along a horizontal direction.

Abstract: The present disclosure provides a method of preparing a radio frequency filter, including: a substrate; a supporting electrode protruded on a front surface of the substrate; and a thin film structure formed on the substrate and spaced with the substrate by the supporting electrode. An end surface of a top end of the supporting electrode is in sealing contact with a front surface of the thin film structure.

Abstract: Provided are a solidly mounted resonator and a method for preparing a solidly mounted resonator. The solidly mounted resonator includes: a piezoelectric structure, wherein the piezoelectric structure includes: an upper electrode layer, a lower electrode layer and a piezoelectric layer. The lower electrode layer disposed corresponding to the piezoelectric structure, and the lower electrode layer includes: a protruding portion protruding downward corresponding to a lower surface of the lower electrode layer; the piezoelectric layer is disposed on an upper surface of the lower electrode layer; the upper electrode layer is disposed on an upper surface of the piezoelectric layer.

Abstract: The present disclosure provides a radio frequency filter, including: a substrate; a supporting electrode protruded on a front surface of the substrate; and a thin film structure formed on the substrate and spaced with the substrate by the supporting electrode. An end surface of a top end of the supporting electrode is in sealing contact with a front surface of the thin film structure.

Abstract: An acoustic wave device including: a POI structure including: a material layer where a high acoustic velocity layer and a low acoustic velocity layer are alternate, a substrate is a lowermost high acoustic velocity layer; a first piezoelectric layer located above the material layer, wherein a layer adjacent to the first piezoelectric layer is referred to as a surface low acoustic velocity layer; wherein an acoustic velocity of a bulk wave propagated in the high acoustic velocity layer and the low high acoustic velocity layer is higher than and lower than an acoustic velocity of a bulk wave of the first piezoelectric layer, respectively. The POI structure includes at least two regions, a first device having a resonance of a first vibration mode is manufactured in the first region, and a second device having a resonance of a second vibration mode is manufactured in a second region.

Abstract: A method of manufacturing a bulk acoustic wave filter is provided, including: forming an acoustic reflection air cavity, a sacrificial layer, a seed layer, a lower electrode layer and a piezoelectric layer of n resonators on a substrate in sequence, wherein n is greater than or equal to 2; taking N from 1 to n for respectively repeating following steps: forming an N-th metal hard mask layer, defining an effective area of a first resonator to an N-th resonator by using a photolithography process, removing the N-th metal hard mask layer outside the effective area of the first resonator to the N-th resonator, oxidizing the piezoelectric layer outside the effective area of the first resonator to the N-th resonator to form an N-th oxidized part of the piezoelectric layer, and etching the N-th oxidized part of the piezoelectric layer; removing the metal hard mask layer of the effective area of the first resonator to the N-th resonator, so as to form the piezoelectric layer having different thicknesses of the first

Abstract: A chip encapsulation structure, including: a wafer provided with a groove; a first metal wire arranged on surfaces of the groove and the wafer; a metal solder ball arranged on the first metal wire or on a metal pad of the chip, and is configured to solder the metal pad of the chip to the first metal wire; a first plastic encapsulation film covering upper surfaces of the wafer, the chip and the first metal wire, and entering a gap between a periphery of a functional area of the chip and the first metal wire, so as to form a closed cavity among the wafer, the groove and the chip; an inductive structure arranged on an upper surface of the first plastic encapsulation film and/or a lower surface of the wafer, and connected to the chip through the first metal wire; and a pad arranged on the inductive structure.

Abstract: The present disclosure provides a bulk acoustic wave resonator, a manufacturing method thereof, and a filter, wherein the bulk acoustic wave resonator includes: a substrate; an acoustic reflection unit on the substrate; a piezoelectric stack structure on the acoustic reflection unit; and a pad on the piezoelectric stack structure; wherein the pad has an overlapping region with the acoustic reflection unit. The acoustic wave resonator, the manufacturing method thereof and the filter of the present disclosure can effectively reduce connection resistance of the bulk acoustic wave resonator, thereby reducing insertion loss of the filter.

Abstract: The surface of the MEMS piezoelectric transducer that optimizes the capacitor shape of the present application is covered with m groups of capacitor (101, 102, 103, 104, 109), m being a natural number ?2. When the MEMS piezoelectric transducer is loaded with a certain load, a stress of a region covered by any one of a first group of capacitors>a stress of a region covered by any one of a second group of capacitors> . . . >a stress of a region covered by any one of a (m?1)th group of capacitors>a stress of a region covered by any one of a mth group of capacitors. Capacitors of the same group are connected in series and/or in parallel; capacitors of different groups are connected in series. The present application performs optimization design to the shape, position and number of the capacitor based on the stress distribution of the MEMS piezoelectric transducer when a certain load is loaded.

Abstract: The present disclosure provides a bulk acoustic wave resonator, a manufacturing method thereof, and a filter, wherein the bulk acoustic wave resonator includes: a substrate; an acoustic reflection unit on the substrate; a piezoelectric stack structure on the acoustic reflection unit; and a pad on the piezoelectric stack structure; wherein the pad has an overlapping region with the acoustic reflection unit. The acoustic wave resonator, the manufacturing method thereof and the filter of the present disclosure can effectively reduce connection resistance of the bulk acoustic wave resonator, thereby reducing insertion loss of the filter.

Abstract: A hybrid acoustic resonator. An interdigital electrode is provided in a first region of a surface of a piezoelectric film facing away from a substrate, and forms an interdigital transducer. At least two trenches are provided in a second region of the surface of the piezoelectric film facing away from the substrate. A bulk-acoustic-wave propagation portion is formed between adjacent trenches. A bulk-acoustic-wave electrode is provided on a side surface of the bulk-acoustic-wave propagation portion, and there is an air gap at a surface of the bulk-acoustic-wave electrode facing away from the bulk-acoustic-wave propagation portion. Thereby, the hybrid acoustic resonator includes both the surface acoustic resonator and the bulk acoustic resonator. An acoustic wave in the bulk-acoustic-wave propagation portion and an acoustic wave in the interdigital transducer are both transmitted along a transversal direction.

Abstract: A hybrid acoustic resonator. An interdigital electrode is provided in a first region of a surface of a piezoelectric film facing away from a substrate, and forms an interdigital transducer. At least two trenches are provided in a second region of the surface of the piezoelectric film facing away from the substrate. A bulk-acoustic-wave propagation portion is formed between adjacent trenches. A bulk-acoustic-wave electrode is provided on a side surface of the bulk-acoustic-wave propagation portion, and there is an air gap at a surface of the bulk-acoustic-wave electrode facing away from the bulk-acoustic-wave propagation portion. Thereby, the hybrid acoustic resonator includes both the surface acoustic resonator and the bulk acoustic resonator. An acoustic wave in the bulk-acoustic-wave propagation portion and an acoustic wave in the interdigital transducer are both transmitted along a transversal direction.

Abstract: A piezoelectric acoustic resonator with an adjustable temperature compensation capability is disclosed. The piezoelectric acoustic resonator includes: a piezoelectric acoustic reflection structure, a first electrode, a second electrode, a piezoelectric layer between the first electrode and the second electrode, and a temperature compensation layer; wherein the temperature compensation layer is a single-layer temperature compensation layer formed of SixOy material, or a composite temperature compensation layer formed by stacking material with a positive temperature coefficient of sound velocity and material with a negative temperature coefficient of sound velocity; and the temperature compensation layer is configured to: perform reverse compensation for a temperature frequency shift caused by the first electrode, the piezoelectric layer and the second electrode in the piezoelectric acoustic resonator; wherein x:y is not equal to 1:2.

Abstract: A piezoelectric acoustic resonator with an adjustable temperature compensation capability is disclosed. The piezoelectric acoustic resonator includes: a piezoelectric acoustic reflection structure, a first electrode, a second electrode, a piezoelectric layer between the first electrode and the second electrode, and a temperature compensation layer; wherein the temperature compensation layer is a single-layer temperature compensation layer formed of SixOy material, or a composite temperature compensation layer formed by stacking material with a positive temperature coefficient of sound velocity and material with a negative temperature coefficient of sound velocity; and the temperature compensation layer is configured to: perform reverse compensation for a temperature frequency shift caused by the first electrode, the piezoelectric layer and the second electrode in the piezoelectric acoustic resonator; wherein x:y is not equal to 1:2.