CN211405986U - Bulk acoustic wave resonator and filter - Google Patents
Bulk acoustic wave resonator and filter Download PDFInfo
- Publication number
- CN211405986U CN211405986U CN201922380231.0U CN201922380231U CN211405986U CN 211405986 U CN211405986 U CN 211405986U CN 201922380231 U CN201922380231 U CN 201922380231U CN 211405986 U CN211405986 U CN 211405986U
- Authority
- CN
- China
- Prior art keywords
- electrode
- capacitor
- acoustic wave
- bulk acoustic
- layer
- 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.)
- Active
Links
Images
Landscapes
- Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)
Abstract
The utility model discloses a bulk acoustic wave resonator, which is provided with an epitaxial substrate, a bonding layer, a supporting layer, a bottom electrode, a piezoelectric film, a top electrode and a dielectric layer from bottom to top in sequence; the upper surface of the piezoelectric film is also provided with a capacitor lower electrode which is not coincident with the position of the top electrode, the dielectric layer is coated on the outer surface of the capacitor lower electrode, and the upper surface of the top electrode is exposed out of the dielectric layer; and the upper surface of the dielectric layer is provided with a capacitor upper electrode, and the orthographic projection of the capacitor lower electrode is superposed with that of the capacitor upper electrode. The utility model discloses a filter, which comprises a plurality of bulk acoustic wave resonators, a substrate and a radio frequency capacitor element, wherein the bulk acoustic wave resonators are arranged on the substrate in a plane manner, at least two bulk acoustic wave resonators are connected in series, the two bulk acoustic wave resonators are connected in parallel, and the upper surfaces of top electrodes of the bulk acoustic wave resonators connected in parallel are provided with thickening layers; the radio frequency capacitor element is connected with the bulk acoustic wave resonator. The utility model provides high wave filter's outband rejection characteristic reduces the performance loss that external circuit introduced.
Description
Technical Field
The utility model relates to a film bulk acoustic wave resonator filter technical field especially relates to a film bulk acoustic wave resonator filter.
Background
The radio frequency signal processing, transferring, transmitting and receiving are the most important rings in the field of information communication in the 5G era, and the construction of a signal transmission system with low delay, high bandwidth and high reliability is extremely important, and the basis is a signal device at the bottom layer, and a filter is one of the key components.
The specific structure of the film bulk acoustic wave resonant filter is a sandwich structure formed by the upper capacitor lower electrode layer and the piezoelectric film together. By utilizing the piezoelectric property of the piezoelectric film, when an alternating voltage is applied to the piezoelectric film through the upper capacitor lower electrode, the piezoelectric film generates mechanical vibration through the piezoelectric effect. The inverse piezoelectric effect is applied to the FBAR filter. When an electric field is applied to a material, the material is mechanically deformed, and when the applied electric field is an alternating electric field, mechanical vibration is generated. The piezoelectric film in the FBAR resonator generates mechanical vibration under the alternating electric field of the upper capacitor lower electrode, and the thickness of the piezoelectric film is constant, so that standing waves can be generated in the piezoelectric film only by vibration sound waves caused by signals of a specific frequency, and the signal frequency is called as the resonance frequency of the FBAR resonator.
The mainstream cavity type FBAR filter is a topology structure formed by connecting a plurality of FBAR resonators in series and in parallel, but this method has problems of large insertion loss, poor out-of-band rejection, and the like when forming a high-order filter and a high-frequency filter. How to coordinate the relationship between in-band insertion loss and out-of-band rejection through the radio frequency capacitor component which is easy to process and prepare is the key point for preparing the FBAR filter.
SUMMERY OF THE UTILITY MODEL
In order to overcome the defects of the prior art, the utility model aims to provide a bulk acoustic wave resonator and filter thereof improves the outband rejection characteristic of bulk acoustic wave resonator filter, reduces the performance loss that external circuit introduced.
The utility model discloses an one of the purpose adopts following technical scheme to realize:
a bulk acoustic wave resonator comprises an epitaxial substrate, a bonding layer, a supporting layer, a bottom electrode, a piezoelectric film, a top electrode and a dielectric layer which are sequentially distributed from bottom to top; the upper surface and the lower surface of the piezoelectric film are respectively connected with a top electrode and a bottom electrode which are opposite, the top electrode, the piezoelectric film and the bottom electrode form a sandwich structure, and the epitaxial substrate, the bonding layer and the bottom electrode form an air gap structure in a surrounding mode; the upper surface of the piezoelectric film is also provided with a capacitor lower electrode which is not coincident with the position of the top electrode, the dielectric layer is coated on the outer surface of the capacitor lower electrode, and the upper surface of the top electrode is exposed out of the dielectric layer; and a capacitor upper electrode is arranged on the upper surface of the dielectric layer, and the orthographic projection of the capacitor lower electrode and the capacitor upper electrode is superposed.
Furthermore, a filling and leveling layer is arranged between the bonding layer and the piezoelectric film, the filling and leveling layer is positioned on the outer side of the bottom electrode, and the thickness of the filling and leveling layer is the same as that of the bottom electrode.
Furthermore, the bottom electrode and the top electrode, and the capacitor upper electrode and the capacitor lower electrode are all made of metal materials, the metal materials comprise one or more of platinum Pt, molybdenum Mo, titanium Ti, aluminum Al and gold Au, and the piezoelectric film is aluminum nitride AlN; the bonding layer and the dielectric layer are made of silicon dioxide SiO2。
The second purpose of the utility model is realized by adopting the following technical scheme:
a filter comprises a plurality of bulk acoustic wave resonators, a substrate and a radio frequency capacitor element, wherein the bulk acoustic wave resonators are arranged on the substrate in a planar mode, at least two bulk acoustic wave resonators are connected in series, at least two bulk acoustic wave resonators are connected in parallel, and a thickening layer is arranged on the upper surface of a top electrode of the bulk acoustic wave resonators connected in parallel; the radio frequency capacitance element is connected with the bulk acoustic wave resonator.
Further, the radio frequency capacitor element comprises a compensation capacitor path and a radio frequency capacitor, the compensation capacitor path comprises a capacitor upper electrode, a capacitor lower electrode and a dielectric layer, and the capacitor upper electrode is connected with the bottom electrode of the bulk acoustic wave resonator in parallel.
Further, the thickness of the dielectric layer is 150 nm-3.5 μm, the thickness of the capacitor upper electrode is 100 nm-2 μm, and the thickness of the capacitor lower electrode is 30 nm-1 μm; the thickness of the bonding layer is 1-4 mu m; the thickness of the piezoelectric film is 100 nm-2 mu m.
Compared with the prior art, the beneficial effects of the utility model reside in that:
the utility model provides a bulk acoustic wave syntonizer and filter thereof adds electric capacity upper electrode and electric capacity bottom electrode, is connected with radio frequency capacitance element, can improve 10dB with outband suppression under the condition that does not influence the in-band insertion loss in the four-order FBAR filter, reduces the performance loss that external circuit introduced.
Drawings
Fig. 1 is a schematic structural diagram of a first embodiment of the present invention;
fig. 2 is a cross-sectional view of a first wafer according to a first embodiment of the present invention;
fig. 3 is a cross-sectional view of a second wafer according to one embodiment of the present invention;
fig. 4 is a cross-sectional view of a bottom electrode prepared according to a first embodiment of the present invention;
fig. 5 is a cross-sectional view of a bonding layer prepared according to a first embodiment of the present invention;
fig. 6 is a cross-sectional view illustrating bonding of a first wafer and a second wafer according to a first embodiment of the present invention;
fig. 7 is a schematic topology diagram of a connection between a single acoustic wave resonator and a radio frequency capacitor according to a second embodiment of the present invention;
fig. 8 is a parameter comparison diagram of a resonator prepared by metal bonding with the same structural parameters according to a first embodiment of the present invention;
in the figure: 101. an epitaxial substrate; 102. a piezoelectric film; 103. a bottom electrode; 104. filling and leveling the layer; 105. a support layer; 106. a bonding layer; 107. a top electrode; 108. a capacitive lower electrode; 109. a dielectric layer; 110. thickening the layer; 111. and a capacitor upper electrode.
Detailed Description
The present invention will be further described with reference to the accompanying drawings and the detailed description, and it should be noted that the embodiments or technical features described below can be arbitrarily combined to form a new embodiment without conflict.
Example 1
The utility model provides a bulk acoustic wave resonator, which is provided with an epitaxial substrate 101, a bonding layer 106, a bottom electrode 103, a piezoelectric film 102, a top electrode 107 and a dielectric layer 109 from bottom to top; the upper surface and the lower surface of the piezoelectric film 102 are respectively connected with a top electrode 107 and a bottom electrode 103 which are opposite, the top electrode 107, the piezoelectric film 102 and the bottom electrode 103 form a sandwich structure, and the epitaxial substrate 101, the bonding layer 106 and the bottom electrode 103 enclose an air gap structure; the upper surface of the piezoelectric film 102 is further provided with a capacitor upper electrode 111 which is not overlapped with the top electrode 107, the dielectric layer 109 covers the outer surface of the capacitor upper electrode 111, and the upper surface of the top electrode 107 is exposed out of the dielectric layer 109; a capacitor lower electrode 108 is arranged on the upper surface of the dielectric layer 109, and the orthographic projection of the capacitor lower electrode 108 and the orthographic projection of the capacitor upper electrode 111 coincide.
As shown in fig. 1, a cavity is formed on the top surface of the epitaxial substrate 101, the bonding layer 106 and a part of the epitaxial substrate 101 form a cavity wall, a filling-up layer 104 is further disposed between the bonding layer 106 and the piezoelectric film 102, and the filling-up layer 104 is located outside the bottom electrode 103, has the same thickness as the bottom electrode 103, and is used for filling up a gap between the piezoelectric film 102 and the bonding layer 106. And the bottom electrode 103 is located at the top end of the cavity, and the width of the bottom electrode 103 is the same as the width of the cavity.
A bonding layer 106 is disposed on the top surface of the epitaxial substrate 101, and a support layer 105 is further disposed between the bonding layer 106 and the fill-and-level layer 104. The bonding layer 106 and the supporting layer 105 both adopt silicon dioxide SiO2Compared with the traditional metal bonding, the bonding method can effectively avoid the introduction of extra parasitic capacitance, has high bonding strength and good mechanical stability, improves the response speed and reduces the electric leakage risk. An air gap structure is formed by the bonding layer 106, the bottom electrode 103 and the epitaxial substrate 101 in a surrounding mode, a sacrificial layer is not required to be introduced, and the production and preparation process is simplified.
The upper surface of the piezoelectric film 102 is further provided with a capacitor upper electrode 111 which is not overlapped with the top electrode 107, and the capacitor lower electrode 108 is covered in the dielectric layer 109. An upper electrode capacitor is also arranged on the top surface of the dielectric layer 109, and the orthographic projection of the upper electrode capacitor and the orthographic projection of the lower electrode capacitor are superposed and are used for being connected with a radio frequency capacitor in the filter.
The main material of the epitaxial substrate 101 is single-crystal high-resistance silicon, the piezoelectric film 102 is made of zinc oxide ZnO, aluminum nitride AlN or piezoelectric ceramic, and the top electrode 107 and the bottom electrode 103 are made of metal materials, wherein the metal materials include one or more of platinum Pt, molybdenum Mo, tungsten W, titanium Ti, aluminum Al and gold Au. In the present embodiment, since the piezoelectric film 102 determines the resonant frequency, and the sound velocity and the temperature coefficient have a large influence on the resonant frequency of the device, the piezoelectric film 102 uses the aluminum nitride AlN, and the resonant frequency is high and the temperature coefficient is low. The electrode material needs to have lower resistivity and density to reduce the electrical loss and mechanical loss of the acoustic wave resonator, respectively, so the top electrode 107 and the bottom electrode 103 adopt a metal material molybdenum Mo. The dielectric layer 109 is silicon dioxide SiO2。
The thickness of the dielectric layer 109 is 150 nm-3.5 μm, the thickness of the capacitor upper electrode 111 is 100 nm-2 μm, and the thickness of the capacitor lower electrode 108 is 30 nm-1 μm; the thickness of the bonding layer 106 is 1-4 μm; the thickness of the piezoelectric film 102 is 100nm to 2 μm. The thickness of the top electrode 107 and the bottom electrode 103 may be 50nm to 500nm, and the thickness of the piezoelectric film 102 may be 200nm to 3 μm. In this embodiment, the bonding layer 106 and the supporting layer 105 have a thickness of 2.3 μm, the top electrode 107 and the bottom electrode 103 are both 380nm, and the piezoelectric film 102 has a thickness of 2 μm.
The utility model also provides a preparation method of above-mentioned bulk acoustic wave syntonizer, including following step:
s1, selecting a monocrystalline silicon or gallium nitride GaN polished wafer as the epitaxial substrate 101, cleaning the epitaxial substrate 101, and removing surface impurities; and preparing a cavity on the surface of the epitaxial substrate 101 through photoetching to generate a first wafer. The epitaxial substrate 101 is cleaned by passing it through a dense H2SO4：H2O2：H2Cleaning SPM solution with O1.5: 1.5:4 at 60 deg.C for 10min, and using H2O: and cleaning with BOE solution of HF (20: 1) for 5min to remove organic matters and dirt on the surface of the epitaxial substrate 101. After the cleaning is completed, the epitaxial substrate 101 is dry etched by lithography RIE in combination with ICP to prepareSuch as the cavity shown in fig. 2.
S2, depositing a bonding layer 106 on the first wafer through photoetching and PECVD, wherein the thickness of the bonding layer 106 is 1-4 mu m, and the material is silicon dioxide SiO as shown in figure 62。
S3, selecting another monocrystalline silicon or GaN and gallium nitride polished wafer as a transfer substrate, cleaning the transfer substrate, removing surface impurities, and generating a second wafer; a piezoelectric film 102 and a bottom electrode 103 are sequentially deposited on the upper surface of the second wafer, and a filling layer 104 is deposited around the bottom electrode 103. The cleaning method for the transfer substrate is the same as that for the epitaxial substrate 101, and is not described herein again. And depositing a layer of 100 nm-2 mu m aluminum nitride AlN piezoelectric film 102 on the upper surface of the second wafer by PECVD, PLD or ALD and the like, and improving the piezoelectric coupling coefficient by doping. A bottom electrode 103 is sputtered or evaporated on the piezoelectric film 102. And a fill-level layer 104 is deposited around the bottom electrode 103 as shown in fig. 3 and 4.
S4, growing a support layer 105 by PECVD over the fill-level layer 104. As shown in fig. 5, the support layer 105 may be silicon dioxide SiO2Or other non-metallic media.
S5, flip-chip bonding the first wafer and the second wafer with the bonding layer 106 and the support layer 105 as contact surfaces, respectively, and separating the transfer substrate from the piezoelectric film 102. SiO 22Hydrophilic bonding is used for bonding, the annealing temperature is 360 ℃, and the bonding is completed after 4 hours of holding. As shown in fig. 6, the transfer substrate is separated from the piezoelectric thin film 102 by mechanical thinning, dry desiliconization, and chemical cleaning.
And S6, depositing a top electrode 107 and a capacitor lower electrode 108 on the upper surface of the piezoelectric film 102 by sputtering and evaporation. The top electrode 107, the piezoelectric film 102 and the bottom electrode 103 form a sandwich structure, and the position of the capacitor lower electrode 108 is not coincident with the position of the bottom electrode 103.
S7, preparing a dielectric layer 109 on the outer surface of the capacitor bottom electrode 108 and around the top electrode 107 by PECVD, wherein the dielectric layer 109 is flush with the surface of the top electrode 107. The material of the dielectric layer 109 is silicon dioxide SiO2。
S8, preparing a capacitor top electrode 111 on the top surface of the dielectric layer 109, and the capacitor bottom electrode 108 and the capacitor top electrode 111 are overlapped in orthographic projection.
S9, if the bulk acoustic wave resonators are used in parallel, a thickening layer 110 needs to be prepared on the upper surface of the dielectric layer 109, and the thickening layer 110 coincides with the orthographic projection of the top electrode 107, so as to obtain the structure diagram shown in fig. 1.
Example 2
The utility model also provides a filter, including a plurality of embodiment 1 the bulk acoustic wave syntonizers with base plate, radio frequency electric capacity component, and the bulk acoustic wave syntonizer plane is arranged in the base plate, and at least two of them the bulk acoustic wave syntonizer is established ties, and at least two of them the bulk acoustic wave syntonizer is parallelly connected, and parallelly connected bulk acoustic wave syntonizer's top electrode 107 upper surface is equipped with thickening layer 110; the radio frequency capacitance element is connected with the bulk acoustic wave resonator.
The radio frequency capacitor element comprises a compensation capacitor path and a radio frequency capacitor, the compensation capacitor path comprises a capacitor upper electrode 111, a capacitor lower electrode 108 and a dielectric layer 109, and the capacitor upper electrode 111 is connected with the bottom electrode 103 of the bulk acoustic wave resonator in parallel. In this embodiment, fig. 7 is a schematic topology diagram of a connection between a single bulk acoustic wave resonator and a radio frequency capacitor. The number of the radio frequency capacitance elements is two, and the bulk acoustic wave resonator is also provided with two capacitance upper electrodes 111 and capacitance lower electrodes 108, a top electrode 107 and a bottom electrode 103. And integrating the compensation capacitor channel with the bulk acoustic wave resonator to prepare the filter.
And the chip containing the filter is connected with the vector network analyzer through the probe table, the scattering parameters of the bulk acoustic wave resonator are optimized through the double-port capacitor, and the scattering parameters are compared with the measurement result of the common bulk acoustic wave resonator with the same structure and size. As shown in fig. 8, the out-of-band rejection of the filter is significantly optimized, and compared with a common bulk acoustic wave resonator filter, the out-of-band rejection is improved by 10dB without affecting the in-band insertion loss, and the product performance of the filter is improved.
The above embodiments are only preferred embodiments of the present invention, and the protection scope of the present invention cannot be limited thereby, and any insubstantial changes and substitutions made by those skilled in the art based on the present invention are all within the protection scope of the present invention.
Claims (6)
1. A bulk acoustic wave resonator is characterized by comprising an epitaxial substrate, a bonding layer, a supporting layer, a bottom electrode, a piezoelectric film, a top electrode and a dielectric layer which are sequentially distributed from bottom to top; the upper surface and the lower surface of the piezoelectric film are respectively connected with a top electrode and a bottom electrode which are opposite, the top electrode, the piezoelectric film and the bottom electrode form a sandwich structure, and the epitaxial substrate, the bonding layer and the bottom electrode form an air gap structure in a surrounding mode; the upper surface of the piezoelectric film is also provided with a capacitor lower electrode which is not coincident with the position of the top electrode, the dielectric layer is coated on the outer surface of the capacitor lower electrode, and the upper surface of the top electrode is exposed out of the dielectric layer; and a capacitor upper electrode is arranged on the upper surface of the dielectric layer, and the orthographic projection of the capacitor lower electrode and the capacitor upper electrode is superposed.
2. The bulk acoustic wave resonator according to claim 1, wherein a filling layer is further disposed between the bonding layer and the piezoelectric film, the filling layer is located outside the bottom electrode, and the thickness of the filling layer is the same as that of the bottom electrode.
3. The bulk acoustic wave resonator according to claim 1, wherein the bottom electrode and the top electrode, and the capacitor top electrode and the capacitor bottom electrode are made of a metal material, the metal material comprises one or more of platinum Pt, molybdenum Mo, titanium Ti, aluminum Al, and gold Au, and the piezoelectric thin film is aluminum nitride AlN; the bonding layer and the dielectric layer are made of silicon dioxide SiO2。
4. A filter, comprising a plurality of bulk acoustic wave resonators according to any one of claims 1 to 3, a substrate, and a radio frequency capacitor, wherein the bulk acoustic wave resonators are arranged in a planar manner on the substrate, and at least two of the bulk acoustic wave resonators are connected in series, at least two of the bulk acoustic wave resonators are connected in parallel, and a thickening layer is arranged on the upper surface of a top electrode of the parallel bulk acoustic wave resonators; the radio frequency capacitance element is connected with the bulk acoustic wave resonator.
5. The filter of claim 4, wherein the RF capacitive element comprises a compensation capacitive path and an RF capacitor, the compensation capacitive path comprises a capacitor top electrode, a capacitor bottom electrode, and a dielectric layer, and the capacitor top electrode is connected to the bottom electrode of the bulk acoustic wave resonator in parallel.
6. The filter of claim 4, wherein the dielectric layer has a thickness of 150nm to 3.5 μm, the capacitor upper electrode has a thickness of 100nm to 2 μm, and the capacitor lower electrode has a thickness of 30nm to 1 μm; the thickness of the bonding layer is 1-4 mu m; the thickness of the piezoelectric film is 100 nm-2 mu m.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201922380231.0U CN211405986U (en) | 2019-12-26 | 2019-12-26 | Bulk acoustic wave resonator and filter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201922380231.0U CN211405986U (en) | 2019-12-26 | 2019-12-26 | Bulk acoustic wave resonator and filter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN211405986U true CN211405986U (en) | 2020-09-01 |
Family
ID=72233135
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201922380231.0U Active CN211405986U (en) | 2019-12-26 | 2019-12-26 | Bulk acoustic wave resonator and filter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN211405986U (en) |
-
2019
- 2019-12-26 CN CN201922380231.0U patent/CN211405986U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111082771A (en) | Bulk acoustic wave resonator, preparation method thereof and filter | |
| US7199504B2 (en) | Film bulk acoustic resonator filter | |
| CN103973258B (en) | Piezoelectric thin film vibrator, filter and duplexer | |
| US9197185B2 (en) | Resonator device including electrodes with buried temperature compensating layers | |
| JP4113637B2 (en) | Acoustic resonator and manufacturing method | |
| WO2021109444A1 (en) | Bulk acoustic resonator, fabrication method therefor, filter and electronic device | |
| EP0973256A1 (en) | Thin film piezoelectric element | |
| WO2020125308A1 (en) | Bulk acoustic resonator and preparation method therefor | |
| JP2003505906A (en) | Resonator structure and filter having the resonator structure | |
| CN113746446B (en) | Bulk acoustic wave resonator with stable frequency function | |
| CN110784188B (en) | Resonator and preparation method thereof | |
| EP4087131A1 (en) | Bulk acoustic wave resonator having electrical isolation layer and manufacturing method therefor, filter, and electronic device | |
| CN103560763A (en) | On-chip integrated body wave resonator and manufacturing method thereof | |
| WO2022143286A1 (en) | Single-crystal acoustic resonator, filter, and electronic device | |
| CN114531126A (en) | Preparation method of broadband film bulk acoustic resonator | |
| CN113708740B (en) | Piezoelectric film bulk acoustic resonator and preparation method thereof | |
| CN111049490A (en) | Bulk acoustic wave resonator with electrical isolation layer, method of manufacturing the same, filter, and electronic apparatus | |
| CN112671367A (en) | Novel FBAR filter and preparation method thereof | |
| WO2022228385A1 (en) | Bulk acoustic wave resonator having thickened electrode, filter, and electronic device | |
| CN114978090A (en) | Bulk acoustic wave filter, communication device, and method for manufacturing bulk acoustic wave filter | |
| CN114978095A (en) | Temperature compensation type film bulk acoustic resonator, manufacturing method thereof and filter | |
| CN116346067B (en) | Cavity type bulk acoustic wave resonator and manufacturing method thereof | |
| CN110957989A (en) | Film bulk acoustic resonator and manufacturing method thereof | |
| CN211405986U (en) | Bulk acoustic wave resonator and filter | |
| CN210273998U (en) | Film bulk acoustic resonator with buffering support structure in cavity and communication device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20220225 Address after: 510700 room 1103, building B2, No. 136, Kaiyuan Avenue, Huangpu District, Guangzhou, Guangdong Patentee after: Guangzhou Everbright Technology Co.,Ltd. Address before: 517000 Zhongtuo optoelectronics Co., Ltd., Gaoxin 5th Road, Heyuan hi tech Development Zone, Guangdong Province Patentee before: HEYUAN CHOICORE PHOTOELECTRIC TECHNOLOGY Co.,Ltd. |
|
| TR01 | Transfer of patent right |