CN112018229A - SAW filter processing and packaging method, SAW filter and communication terminal - Google Patents
SAW filter processing and packaging method, SAW filter and communication terminal Download PDFInfo
- Publication number
- CN112018229A CN112018229A CN202011160246.7A CN202011160246A CN112018229A CN 112018229 A CN112018229 A CN 112018229A CN 202011160246 A CN202011160246 A CN 202011160246A CN 112018229 A CN112018229 A CN 112018229A
- Authority
- CN
- China
- Prior art keywords
- piezoelectric substrate
- interdigital electrode
- cover
- saw filter
- cavity
- 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
Images
Classifications
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N30/00—Piezoelectric or electrostrictive devices
- H10N30/80—Constructional details
- H10N30/88—Mounts; Supports; Enclosures; Casings
-
- 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
- H03H9/64—Filters using surface acoustic waves
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N30/00—Piezoelectric or electrostrictive devices
- H10N30/01—Manufacture or treatment
- H10N30/02—Forming enclosures or casings
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N30/00—Piezoelectric or electrostrictive devices
- H10N30/01—Manufacture or treatment
- H10N30/06—Forming electrodes or interconnections, e.g. leads or terminals
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N30/00—Piezoelectric or electrostrictive devices
- H10N30/80—Constructional details
- H10N30/87—Electrodes or interconnections, e.g. leads or terminals
- H10N30/875—Further connection or lead arrangements, e.g. flexible wiring boards, terminal pins
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)
Abstract
The invention provides a SAW filter processing and packaging method, a SAW filter and a communication terminal, which can be used for respectively arranging corresponding interdigital electrodes on two oppositely arranged first surfaces and second surfaces of a single piezoelectric substrate, thereby realizing the arrangement of different filters on the first surfaces and the second surfaces of the single piezoelectric substrate, improving the number of the filters in a unit area and greatly improving the integration level.
Description
Technical Field
The invention relates to the technical field of integrated circuit processing and packaging, in particular to a SAW filter processing and packaging method, a SAW filter and a communication terminal.
Background
A Surface Acoustic Wave (SAW) filter device is one of the mainstream piezoelectric Acoustic Wave filters at present, and can meet the requirements of small-sized filter devices used in communication terminals.
Due to the fact that the SAW filter technology is mature relatively, the cost is low relatively, and the temperature compensation SAW device is mature day by day, the SAW filter still occupies an advantage in the frequency band application below 2.5GHz of the radio frequency front end, and particularly, the SAW filter is still adopted basically below 2G. For FDD (Frequency Division Duplexing), the SAW duplexer is currently implemented in two forms: (1) as shown in fig. 1, the transmitting end filter Tx and the receiving end filter Rx are independently processed, and then are packaged together in a CSP (Chip Scale Package) manner; (2) as shown in fig. 2, the filter is implemented in a form that the transmitting end filter Tx and the receiving end filter Rx are processed on one wafer at the same time.
However, the two implementation forms of the SAW duplexer have the problems of large packaging area, low integration level and difficulty in meeting the requirement of higher performance of the communication terminal.
Disclosure of Invention
The invention aims to provide a SAW filter processing and packaging method, a SAW filter and a communication terminal, which can improve the number of devices in a unit area and further improve the device integration level.
In order to solve the above technical problem, the present invention provides a SAW filter processing and packaging method, including:
providing a piezoelectric substrate with a first surface and a second surface which are oppositely arranged, forming a first interdigital electrode and a protective layer on the first surface of the piezoelectric substrate, wherein the first interdigital electrode is buried in the protective layer;
forming a second patterned interdigital electrode on the second surface of the piezoelectric substrate, and bonding a first cover body to the second surface of the piezoelectric substrate, wherein a first cavity is formed between the first cover body and the piezoelectric substrate, and the second interdigital electrode is positioned in the first cavity;
and removing the protective layer, bonding a second cover body to the first surface of the piezoelectric substrate, and forming a second cavity between the second cover body and the piezoelectric substrate, wherein the first interdigital electrode is positioned in the second cavity.
Optionally, the first interdigital electrode and the second interdigital electrode are respectively used for forming a transmitting end filter and a receiving end filter of the same SAW duplexer; or the first interdigital electrode and the second interdigital electrode are used for forming SAW filters of different frequency bands.
Optionally, a first bonding member disposed on the periphery of the first interdigital electrode is further formed on the first surface of the piezoelectric substrate, and the second cover body is bonded to the first bonding member; and/or a second key piece arranged on the periphery of the second interdigital electrode is further formed on the second surface of the piezoelectric substrate, and the first cover body is bonded to the second key piece.
Optionally, the first cover and the second cover are both temperature compensation plates having different thermal expansion coefficients from the piezoelectric substrate.
Optionally, the first cover and the second cover are respectively selected from at least one of a silicon substrate, a ceramic substrate, or a glass substrate.
Optionally, a second pad disposed at the periphery of the second interdigital electrode is further formed on the second surface of the piezoelectric substrate, and after the first cover is bonded and before the protective layer is removed, a first conductive plug is formed in the first cover, and the first conductive plug is in electrical contact with the second pad.
Optionally, a first pad disposed on the periphery of the first interdigital electrode is further formed on the first surface of the piezoelectric substrate, and after the second cover is bonded, a second conductive plug is formed in the second cover, and the second conductive plug is in electrical contact with the first pad.
Based on the same inventive concept, the present invention further provides a SAW filter package structure, including:
a piezoelectric substrate having a first surface and a second surface disposed opposite to each other;
a patterned first interdigital electrode formed on a first surface of the piezoelectric substrate;
a patterned second interdigital electrode formed on the second surface of the piezoelectric substrate;
a first cover bonded to the second surface of the piezoelectric substrate with a first cavity formed therebetween, the second interdigital electrode being located in the first cavity;
and the second cover body is bonded to the first surface of the piezoelectric substrate, a second cavity is formed between the second cover body and the piezoelectric substrate, and the first interdigital electrode is positioned in the second cavity.
Optionally, a first pad disposed on the periphery of the first interdigital electrode is further formed on the first surface of the piezoelectric substrate, a second conductive plug is further disposed on the second cover, and the second conductive plug penetrates through the second cover and is electrically contacted with the first pad; and/or a second bonding pad arranged on the periphery of the second interdigital electrode is further formed on the second surface of the piezoelectric substrate, a first conductive plug is further arranged on the first cover body, and the first conductive plug penetrates through the first cover body and is electrically contacted with the second bonding pad.
Based on the same inventive concept, the invention also provides a communication terminal which is provided with the SAW filter packaging structure.
Compared with the prior art, the technical scheme of the invention has at least one of the following beneficial effects:
1. the invention can respectively arrange corresponding interdigital electrodes on the first surface and the second surface which are oppositely arranged on the single piezoelectric substrate, thereby realizing the arrangement of different filters on the first surface and the second surface of the single piezoelectric substrate, improving the number of the filters in unit area and greatly improving the integration level.
2. The first interdigital electrode and the second interdigital electrode on the first surface and the second surface of the single piezoelectric substrate can be respectively used for forming a transmitting end filter and a receiving end filter of the same SAW duplexer, can also be used for forming SAW filters of different frequency bands, and can be determined according to actual conditions, so that the communication requirements of different communication terminals are met.
3. When the piezoelectric substrate is a piezoelectric wafer, since different filters are arranged on the first surface and the second surface of one piezoelectric wafer, more efficient Wafer Level Package (WLP) can be realized, the use of the piezoelectric wafer can be saved, and the package difficulty and the package cost are both reduced.
Drawings
Fig. 1 and fig. 2 are schematic cross-sectional structural diagrams of devices in two implementation forms of a conventional SAW duplexer.
Fig. 3 is a flow chart illustrating a SAW filter processing and packaging method according to an embodiment of the present invention.
Fig. 4 to 10 are schematic cross-sectional views of devices in a SAW filter processing and packaging method according to an embodiment of the present invention.
Detailed Description
The technical solution proposed by the present invention will be further described in detail with reference to fig. 3 to 10 and the specific embodiments. The advantages and features of the present invention will become more apparent from the following description. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention. Fig. 4 to 10 are schematic cross-sectional structures of only one SAW filter region, and those skilled in the art can extend the structures in other SAW filter regions distributed on the entire piezoelectric wafer according to the structures shown in fig. 4 to 10.
Referring to fig. 3, an embodiment of the invention provides a SAW filter processing and packaging method, including:
s1, providing a piezoelectric substrate with a first surface and a second surface which are oppositely arranged, forming a first interdigital electrode, a first pad and a protective layer on the first surface of the piezoelectric substrate, wherein the protective layer buries the first interdigital electrode and the first pad;
s2, forming second interdigital electrodes and second bonding pads in a patterned mode on the second surface of the piezoelectric substrate, and bonding a first cover body to the second surface of the piezoelectric substrate, wherein a first cavity is formed between the first cover body and the piezoelectric substrate, and the second interdigital electrodes are located in the first cavity;
s3, forming a first conductive plug in the first cover, the first conductive plug electrically contacting the second pad;
s4, removing the protective layer, and bonding a second cover to the first surface of the piezoelectric substrate, wherein a second cavity is formed between the second cover and the piezoelectric substrate, and the first interdigital electrode is located in the second cavity;
and S5, forming a second conductive plug in the second cover body, wherein the second conductive plug is electrically contacted with the first bonding pad.
Referring to fig. 4, in step S1, first, a piezoelectric substrate 200 having a first surface 200a and a second surface 200b opposite to each other is provided, and the piezoelectric substrate 200 may be a piezoelectric material such as quartz crystal, lithium niobate crystal, lithium tantalate crystal, ZnO polycrystal, AlN material, and the like, capable of generating a piezoelectric effect to generate a surface acoustic wave on the surface of the piezoelectric substrate 200. The piezoelectric substrate 200 is a wafer-level sheet. Preferably, the piezoelectric substrate 200 is provided as a double-side polished and cleaned piezoelectric wafer, the first surface 200a and the second surface 200b of which are both clean and flat. At this time, the first surface 200a of the piezoelectric substrate 200 faces upward and the second surface 200b faces downward.
Then, with continued reference to fig. 4, in step S1, an electrode metal material is coated on the first surface 200a of the piezoelectric substrate 200 by a vacuum evaporation or sputtering deposition process, wherein the electrode metal material is selected from metal materials known to those skilled in the art for making electrodes, and may include at least one of tungsten, silver, zirconium, molybdenum, platinum (i.e., platinum), ruthenium, iridium, titanium, tungsten, copper, chromium, hafnium, and aluminum, for example. Then, the electrode metal material is patterned by a process of photolithography combined with dry etching to form a patterned first interdigital electrode 201a, a first bonding member 201b located at the periphery of the first interdigital electrode 201a, and a first bonding pad 201c located between the first interdigital electrode 201a and the first bonding member 201b, wherein the first bonding member 201b is used for performing bump bonding with a bonding pad on the second cover body in a subsequent packaging process, which may be a ring structure enclosing the first bonding pad 201c and the first interdigital electrode 201 a. The first interdigital electrode 201a is an electrode having a periodic pattern in its plane, such as a finger or comb, which is used to form a SAW filter. The first interdigital electrodes 201a are usually present in pairs, so that an input electrical signal excites a surface acoustic wave by the piezoelectric effect of one first interdigital electrode and propagates to the other first interdigital electrode, the surface acoustic wave is converted into an electrical signal at the other first interdigital electrode for output due to the inverse piezoelectric effect, and a desired bandpass filter frequency response curve can be obtained by controlling the parameters such as the period, the shape and the like of the first interdigital electrode 201 a. The first pad 201c is used to lead the first interdigital electrode 201a outward to input an electric signal to the first interdigital electrode 201a or output an electric signal of the first interdigital electrode 201a outward.
In other embodiments of the present invention, the first interdigital electrode 201a, the first pad 201c, and the first bonding member 201b may also be formed by a Lift-off process, in which a first surface 200a of the piezoelectric substrate 200 is coated with glue and then subjected to photolithography, and then a metal thin film is prepared, where the photoresist is present, the metal thin film is formed on the photoresist, and where the photoresist is absent, the metal thin film is directly formed on the piezoelectric substrate 200. When the photoresist on the piezoelectric substrate 200 is removed by using a solvent, unnecessary metal is removed in the solvent as the photoresist is dissolved, and the metal portion directly formed on the piezoelectric substrate 200 remains to form a pattern, that is, the first interdigital electrode 201a, the first pad 201c, and the first bonding member 201 b.
It should be understood that, although in this embodiment, the first interdigital electrode 201a, the first bonding member 201b, and the first bonding pad 201c are all made of the same film layer and have the same thickness, the technical solution of the present invention is not limited thereto, and in other embodiments of the present invention, the first interdigital electrode 201a, the first bonding member 201b, and the first bonding pad 201c may also be made of different film layers sequentially, in which case, the first interdigital electrode 201a, the first bonding member 201b, and the first bonding pad 201c may have different thicknesses and be made of different materials, for example, the first interdigital electrode 201a is Al (aluminum), the first bonding member 201b is Au (gold) or an alloy containing Au, and the first bonding pad 201c is Cu (copper).
In addition, in this embodiment, parameters such as the thickness, the length, and the line width of each of the mutually discrete first interdigital electrodes 201a are substantially the same, thereby implementing a SAW filter of a single frequency band. However, the technical solution of the present invention is not limited thereto, and in other embodiments of the present invention, arbitrary parameters of the thickness, the length, the line width, and the like of the respective mutually discrete first interdigital electrodes 201a may not be completely the same, thereby integrating filters of different frequency bands on the first surface of the piezoelectric substrate 200 to further realize a small-sized, simple-to-manufacture, and easily-integrated multi-mode SAW filter.
Referring to fig. 5, in step S1, after the patterned first interdigital electrode 201a, the patterned first bonding member 201b, and the first bonding pad 201c are formed, a protective layer 202 may be coated on the piezoelectric substrate 200 and the patterned first interdigital electrode 201a, the patterned first bonding member 201b, and the patterned first bonding pad 201c by a suitable film forming process such as coating or vapor deposition, and a surface of the protective layer 202 facing away from the first surface 200a may be further planarized, where the protective layer 202 buries the patterned first interdigital electrode 201a, the patterned first bonding pad 201c, and the patterned first bonding pad 201 b. The material of the protection layer 202 may include at least one of photoresist, silicon dioxide, silicon nitride, silicon oxynitride, low-K dielectric having a dielectric constant K lower than that of silicon dioxide, high-K dielectric having a dielectric constant K higher than that of silicon dioxide, and the like.
Referring to fig. 6, in step S2, first, the piezoelectric substrate 200 is inverted to face the first surface 200a of the piezoelectric substrate 200 downward and the second surface 200b upward; then, according to the method for forming the first interdigital electrode 201a, the first bonding member 201b, and the first bonding pad 201c, the patterned second interdigital electrode 203a, the patterned second bonding pad 203c, and the patterned second interdigital electrode 203b may be formed on the second surface 200b of the piezoelectric substrate 200, and the specific process may refer to the above description, which is not repeated herein. The second interdigital electrode 203a may be made of the same material as the first interdigital electrode 201a, or may be made of a different material. The pattern of the second interdigital electrode 203a may be the same as or different from that of the first interdigital electrode 201 a.
As an example, the first interdigital electrode 201a and the second interdigital electrode 203a are respectively used for forming a transmitting terminal SAW filter and a receiving terminal SAW filter of the same SAW duplexer, and at this time, the operating frequency bands of the SAW filters formed by the first interdigital electrode 201a and the second interdigital electrode 203a are the same, so that the SAW duplexer can be implemented in the same crystal grain after the subsequent crystal grain cutting of the piezoelectric substrate 200. As another example, the first interdigital electrode 201a and the second interdigital electrode 203a are respectively used for forming SAW filters of different frequency bands, so that after the piezoelectric substrate 200 is subsequently subjected to die cutting, SAW filters of different frequency bands can be integrated in the same die, and a specific frequency band combination can be determined according to actual communication requirements of devices.
With continued reference to fig. 7, in step S2, after forming the second interdigital electrode 203a, the second bonding member 203b, and the second bonding pad 203c, first, a first cover 205 having a first corresponding element 205a for bonding is provided, the first cover 205 further has a portion 205b aligned with the bonding pad 203c and used for making a first conductive plug, and a gap 205c is provided between the portion 205b of the first cover 205 and the first corresponding element 205a, which can prevent a subsequently formed first conductive plug from being electrically connected to an electrical structure on the periphery of the second bonding member 203b through a bonding interface; then, using a bonding process conventional in the art, the first cover 205 and the second surface 200b of the piezoelectric substrate 200 are aligned, and the first counterpart 205a and the second bonding member 203b may be bonded to each other by a bonding process conventional in the art, so that the first cover 205 and the second surface 200b of the piezoelectric substrate 200 are bonded to each other, whereby the piezoelectric substrate 200, the second bonding member 203b, the first counterpart 205a, and the first cover 205 together form a sealed first cavity 206, and the first cavity 206 receives the second interdigital electrode 203a therein.
The first cap 205 may be made of any suitable cap material known to those skilled in the art, such as a silicon substrate, a Ceramic substrate, or a glass substrate, wherein the Ceramic substrate may be a Low Temperature Co-fired Ceramic (LTCC) substrate, or a High Temperature Co-fired Ceramic (HTCC) substrate, the LTCC substrate refers to a Ceramic substrate formed by sintering a multi-layer structure of a via material, a thick film electrode, an interconnect material, a passive component, and the like at a Low Temperature (950 ℃ or less) according to a pre-designed structure, and the HTCC substrate is a Ceramic substrate made of aluminum oxide, aluminum nitride, and the like, and the sintering Temperature is generally higher than 1000 ℃. The glass substrate may be silicon dioxide, phosphosilicate glass, borosilicate glass, or the like. The surface of the first cover 205 facing the piezoelectric substrate 200 may have a planar structure or a structure having a groove. The position and material of the first counterpart 205a need to match the second bonding element 203b, and the material of the first counterpart 205a is, for example, gold or tin. The first counter piece 205a and the second bonding piece 203b may be bonded to each other by melt diffusion or by bonding with the conductive adhesive 204.
Referring to fig. 8, in step S3, a conventional contact hole etching and filling process or a redistribution layer (RDL) process may be used to form a contact hole (not shown) in the portion 205b of the first cover 205 aligned with the second pad 203c, the contact hole exposing a portion of the surface of the second pad 203c, and the contact hole is filled with a conductive material such as copper to form the first conductive plug 207. The first cover 205 is provided so as to form a first cavity 206 with the piezoelectric substrate 200 and to lead out the second land 203 c. In the present embodiment, when the second bonding member 203b and the first counterpart 205a are bonded, the second pad 203c and the portion 205b of the first cover 205 are also bonded to each other, and the portion 205b of the first cover 205 and the second pad 203c together form a part of or the entire side wall of the first cavity 206. The first conductive plugs 207 lead out the second interdigital electrodes 203a together with the second pads 203 c.
Optionally, before or after forming the first conductive plug 207, a first molding compound layer (not shown) is formed on the second surface 200b of the piezoelectric substrate 200 by a conventional injection molding process, the first molding compound layer encloses the exposed surfaces of the first cover 205, the second interdigital electrode 203a, the second bonding member 203b, the first counterpart 205a, and the like, which are disposed on the second surface 200b of the piezoelectric substrate 200, and the first molding compound layer may finally expose a part of the surface of the first conductive plug 207. After the first cover 205 is bonded and before the first conductive plug 207 is formed, the first molding layer is formed, so that sufficient mechanical supporting force can be provided for the piezoelectric substrate 200 in the subsequent steps, existing structures on the second surface 200b of the piezoelectric substrate 200 can be protected in the subsequent steps, and the problems that the existing structures are damaged by processes in the subsequent steps are solved.
Referring to fig. 9 and 10, in step S4, first, the piezoelectric substrate 200 is inverted so that the first surface 200a of the piezoelectric substrate 200 faces upward and the second surface 200b faces downward; then, depending on the material of the protection layer 202, a suitable removal process, such as dry etching or wet etching, is selected to remove the protection layer 202, and to re-expose the first interdigital electrode 201a, the first pad 201c, and the first bonding member 201 b. Next, a second cover body 208 having a second counterpart 208a is provided, and the second cover body 208 is aligned with the first surface 200a of the piezoelectric substrate 200, and the second counterpart 208a and the first bonding member 201b are bonded to each other using a bonding process that is conventional in the art, such that the second cover body 208 and the piezoelectric substrate 200 are bonded to each other, whereby the piezoelectric substrate 200, the first bonding member 201b, the second counterpart 208a, and the second cover body 208 together form a sealed second cavity 209, and the second cavity 209 receives the first interdigital electrode 201a therein. The second cover 208 may be made of any suitable cover material known to those skilled in the art, and the material and structure thereof may be the same as or different from those of the first cover 205, and the method for providing the second cover 208 with the second corresponding element 208a may be the same as the method for providing the first cover 205 with the first corresponding element 205a, and thus, the description thereof is omitted. The first bonding member 201b and the second corresponding member 208a may be bonded to each other by melting and spreading, or by bonding with a conductive adhesive 210.
With continued reference to fig. 10, in step S5, the second cover 208 may be subjected to photolithography, etching and conductive material filling by using the formation process of the first conductive plug 207, so as to form a second conductive plug 211 in the portion of the second cover 208 aligned with the first pad 201 c. The second conductive plug 211 is electrically contacted with the first pad 201 c.
Optionally, before or after forming the second conductive plug 211, a second molding compound layer (not shown) may be formed on the first surface 200a of the piezoelectric substrate 200 by a conventional injection molding process, the second molding compound layer encloses the exposed surfaces of the second cover 208, the first interdigital electrode 201a, the first bonding member 201b, the second counterpart 208a, and the like, which are disposed on the first surface 200a of the piezoelectric substrate 200, and the second molding compound layer may finally expose a portion of the surface of the second conductive plug 211.
It should be noted that, although the first molding compound layer and the second molding compound layer in the embodiment are formed by two injection molding processes, the technical solution of the present invention is not limited thereto, and in other embodiments of the present invention, when the processes and the device performance allow, steps S1, S2, and S4 may be performed first, then the second molding compound layer is formed on the first surface 200a of the piezoelectric substrate 200 by the injection molding process, and the first molding compound layer is formed on the second surface 200b of the piezoelectric substrate 200, and then steps S3 and S5 are performed. That is, the technical solution of the present invention is not limited to sequentially performing the steps S1 to S5, and the order of performing the steps S1 to S5 can be adaptively adjusted according to the process capability and the device performance requirement.
And then, forming a chip-level (die/chip) SAW filter packaging structure through processes such as ball mounting, grain cutting and the like.
In summary, in the SAW filter processing and packaging method of the present invention, the corresponding interdigital electrodes can be respectively disposed on the first surface and the second surface of the single piezoelectric substrate, which are disposed opposite to each other, so that different filters can be disposed on the first surface and the second surface of the single piezoelectric substrate, thereby increasing the number of filters in a unit area, and greatly improving the integration level. The first interdigital electrode and the second interdigital electrode on the first surface and the second surface of the single piezoelectric substrate can be respectively used for forming a transmitting end filter and a receiving end filter of the same SAW duplexer, can also be used for forming SAW filters of different frequency bands, and can be determined according to actual conditions, so that the communication requirements of different communication terminals are met. In addition, when the piezoelectric substrate is a piezoelectric wafer, since different filters are arranged on the first surface and the second surface of one piezoelectric wafer, more efficient Wafer Level Package (WLP) can be realized, the use of the piezoelectric wafer can be saved, and the package difficulty and the package cost are both reduced.
Referring to fig. 9, an embodiment of the invention provides a SAW filter package structure formed by using the SAW filter processing and packaging method of the invention, where the SAW filter package structure specifically includes: a piezoelectric substrate 200, a patterned first interdigital electrode 201a, a patterned second interdigital electrode 203a, a first cap 205, a second cap 208, a first conductive plug 207, and a second conductive plug 211.
The piezoelectric substrate 200 has a first surface 200a and a second surface 200b which are oppositely arranged, a patterned first interdigital electrode 201a is formed on the first surface 200a of the piezoelectric substrate 200, a patterned second interdigital electrode 203a is formed on the second surface 200b of the piezoelectric substrate 200, a first cap 205 is bonded to the second surface 200b of the piezoelectric substrate 200, a second cap 208 is bonded to the first surface 200a of the piezoelectric substrate 200, a first cavity 206 is formed between the first cap 205 and the second surface 200b of the piezoelectric substrate 200, a second cavity 209 is formed between the second cap 208 and the first surface 200a of the piezoelectric substrate 200, the second interdigital electrode 203a is located in the first cavity 206, and the first interdigital electrode 201a is located in the second cavity 209, the second conductive plug 211 penetrates through the second pad and electrically contacts with the first cap 201c on the first surface 200a, the first conductive plug 207 penetrates through the first cover 205 and electrically contacts the second pad 203c on the second surface 200 b.
Materials and structures of the piezoelectric substrate 200, the patterned first interdigital electrode 201a, the patterned second interdigital electrode 203a, the first cover 205, the second cover 208, the first conductive plug 207, and the second conductive plug 211 may be selected from the above description, and are not described herein again.
The first cover 205 and the second cover 208 may be made of any suitable cover material known to those skilled in the art, and the materials of the two covers may be the same or different.
The SAW filter package structure of this embodiment is a SAW duplexer chip, which may be a SAW duplexer, and at this time, the first interdigital electrode 201a and the second interdigital electrode 203a may be used as a transmitting end filter and a receiving end filter of the SAW duplexer, respectively. In other embodiments of the present invention, the SAW filter package structure of this embodiment is a multi-mode filter chip, and at this time, the first interdigital electrode 201a and the second interdigital electrode 203a are respectively used to form SAW filters of different frequency bands.
An embodiment of the present invention further provides a communication terminal, which includes the SAW filter package structure of the present invention. The communication terminal can be any form of electronic equipment such as a mobile phone, an earphone and a computer.
The above description is only for the purpose of describing the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention, and any variations and modifications made by those skilled in the art according to the above disclosure are within the scope of the present invention.
Claims (10)
1. A method for processing and packaging a SAW filter, comprising:
providing a piezoelectric substrate with a first surface and a second surface which are oppositely arranged, forming a first interdigital electrode and a protective layer on the first surface of the piezoelectric substrate, wherein the first interdigital electrode is buried in the protective layer;
forming a second patterned interdigital electrode on the second surface of the piezoelectric substrate, and bonding a first cover body to the second surface of the piezoelectric substrate, wherein a first cavity is formed between the first cover body and the piezoelectric substrate, and the second interdigital electrode is positioned in the first cavity;
and removing the protective layer, bonding a second cover body to the first surface of the piezoelectric substrate, and forming a second cavity between the second cover body and the piezoelectric substrate, wherein the first interdigital electrode is positioned in the second cavity.
2. A SAW filter processing and packaging method as claimed in claim 1, wherein said first interdigital electrode and said second interdigital electrode are respectively used for forming a transmitting side filter and a receiving side filter of the same SAW duplexer; or the first interdigital electrode and the second interdigital electrode are used for forming SAW filters of different frequency bands.
3. A SAW filter processing and packaging method as claimed in claim 1, wherein a first bonding member disposed at the periphery of said first interdigital electrode is further formed on the first surface of said piezoelectric substrate, and said second cover is bonded to said first bonding member; and/or a second key piece arranged on the periphery of the second interdigital electrode is further formed on the second surface of the piezoelectric substrate, and the first cover body is bonded to the second key piece.
4. A SAW filter processing and packaging method as claimed in claim 1, wherein the first cover and the second cover each include a temperature compensation plate having a different coefficient of thermal expansion from the piezoelectric substrate.
5. The SAW filter processing and packaging method of claim 1, wherein the first cover and the second cover are each selected from at least one of a silicon substrate, a ceramic substrate, or a glass substrate.
6. The SAW filter processing and packaging method as claimed in claim 1, wherein a second land disposed at the periphery of the second interdigital electrode is further formed on the second surface of the piezoelectric substrate, and a first conductive plug is formed in the first cover after bonding the first cover and before removing the protective layer, the first conductive plug being in electrical contact with the second land.
7. A SAW filter processing and packaging method as claimed in claim 1, wherein first pads disposed at the periphery of the first interdigital electrodes are further formed on the first surface of the piezoelectric substrate, and after the second cover is bonded, second conductive plugs are formed in the second cover, the second conductive plugs being in electrical contact with the first pads.
8. A SAW filter package, comprising:
a piezoelectric substrate having a first surface and a second surface disposed opposite to each other;
a patterned first interdigital electrode formed on a first surface of the piezoelectric substrate;
a patterned second interdigital electrode formed on the second surface of the piezoelectric substrate;
a first cover bonded to the second surface of the piezoelectric substrate with a first cavity formed therebetween, the second interdigital electrode being located in the first cavity;
and the second cover body is bonded to the first surface of the piezoelectric substrate, a second cavity is formed between the second cover body and the piezoelectric substrate, and the first interdigital electrode is positioned in the second cavity.
9. A SAW filter package as claimed in claim 8, wherein a first land is further formed on the first surface of the piezoelectric substrate and disposed at the periphery of the first interdigital electrode, and a second conductive plug is further disposed on the second cover, the second conductive plug penetrating the second cover and being in electrical contact with the first land; and/or a second bonding pad arranged on the periphery of the second interdigital electrode is further formed on the second surface of the piezoelectric substrate, a first conductive plug is further arranged on the first cover body, and the first conductive plug penetrates through the first cover body and is electrically contacted with the second bonding pad.
10. A communication terminal characterized by having the SAW filter package structure of claim 8 or 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011160246.7A CN112018229A (en) | 2020-10-27 | 2020-10-27 | SAW filter processing and packaging method, SAW filter and communication terminal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011160246.7A CN112018229A (en) | 2020-10-27 | 2020-10-27 | SAW filter processing and packaging method, SAW filter and communication terminal |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112018229A true CN112018229A (en) | 2020-12-01 |
Family
ID=73528176
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011160246.7A Pending CN112018229A (en) | 2020-10-27 | 2020-10-27 | SAW filter processing and packaging method, SAW filter and communication terminal |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112018229A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112422101A (en) * | 2021-01-21 | 2021-02-26 | 中芯集成电路制造(绍兴)有限公司 | Electronic device and forming method thereof |
| CN113097194A (en) * | 2021-03-30 | 2021-07-09 | 苏州汉天下电子有限公司 | Radio frequency module and preparation method thereof |
| CN113794458A (en) * | 2021-09-16 | 2021-12-14 | 无锡市好达电子股份有限公司 | Surface acoustic wave device with composite film layer |
| CN117728791A (en) * | 2023-06-30 | 2024-03-19 | 荣耀终端有限公司 | Filter, manufacturing process of filter and electronic equipment |
| CN117833857A (en) * | 2024-02-21 | 2024-04-05 | 唯捷创芯(天津)电子技术股份有限公司 | Filter packaging structure and manufacturing method thereof |
-
2020
- 2020-10-27 CN CN202011160246.7A patent/CN112018229A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112422101A (en) * | 2021-01-21 | 2021-02-26 | 中芯集成电路制造(绍兴)有限公司 | Electronic device and forming method thereof |
| CN112422101B (en) * | 2021-01-21 | 2021-04-30 | 中芯集成电路制造(绍兴)有限公司 | Electronic device and forming method thereof |
| WO2022156722A1 (en) * | 2021-01-21 | 2022-07-28 | 绍兴中芯集成电路制造股份有限公司 | Electronic device and formation method therefor |
| CN113097194A (en) * | 2021-03-30 | 2021-07-09 | 苏州汉天下电子有限公司 | Radio frequency module and preparation method thereof |
| CN113794458A (en) * | 2021-09-16 | 2021-12-14 | 无锡市好达电子股份有限公司 | Surface acoustic wave device with composite film layer |
| CN113794458B (en) * | 2021-09-16 | 2023-09-29 | 无锡市好达电子股份有限公司 | Surface acoustic wave device with composite film layer |
| CN117728791A (en) * | 2023-06-30 | 2024-03-19 | 荣耀终端有限公司 | Filter, manufacturing process of filter and electronic equipment |
| CN117833857A (en) * | 2024-02-21 | 2024-04-05 | 唯捷创芯(天津)电子技术股份有限公司 | Filter packaging structure and manufacturing method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112018229A (en) | SAW filter processing and packaging method, SAW filter and communication terminal | |
| US20210044274A1 (en) | Transversely-excited film bulk acoustic resonator package and method | |
| JP6934324B2 (en) | Elastic wave device | |
| JP4460612B2 (en) | Surface acoustic wave device and manufacturing method thereof | |
| JP4248180B2 (en) | Bulk acoustic wave resonator with conductive mirror | |
| CN100571032C (en) | Surface acoustic wave device, acoustic surface wave device and communicator | |
| US7230512B1 (en) | Wafer-level surface acoustic wave filter package with temperature-compensating characteristics | |
| KR20040086189A (en) | Surface acoustic wave device and method of fabricating the same | |
| KR20040110979A (en) | Surface acoustic wave device and method of producing the same | |
| CN110739391B (en) | Surface acoustic wave filter device and method of manufacturing the same | |
| US20210184645A1 (en) | Packaging module and packaging method of baw resonator | |
| US11671072B2 (en) | Multi-layer piezoelectric substrate with conductive layer | |
| US20230179171A1 (en) | Multi-band surface acoustic wave filters | |
| US20230134889A1 (en) | Stacked die transversely-excited film bulk acoustic resonator (xbar) filters | |
| US20230037168A1 (en) | Metal cavity for transversely-excited film bulk acoustic resonator (xbar) | |
| CN101192817A (en) | Acoustic wave device | |
| CN114513180A (en) | Film surface acoustic wave resonator and method for manufacturing the same | |
| WO2023081769A1 (en) | Stacked die transversely-excited film bulk acoustic resonator (xbar) filters | |
| JP7340344B2 (en) | Acoustic wave devices, filters and multiplexers | |
| CN114128142A (en) | Single substrate multiplexer | |
| CN115549624A (en) | Electronic device and manufacturing method thereof | |
| JP7340348B2 (en) | Acoustic wave devices, filters and multiplexers | |
| JP7231368B2 (en) | elastic wave device | |
| JP4458954B2 (en) | Surface acoustic wave device, method of manufacturing the same, and communication device | |
| WO2018221172A1 (en) | Filter device |
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 | ||
| WD01 | Invention patent application deemed withdrawn after publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20201201 |