CN109379056A - A kind of SAW filter - Google Patents
A kind of SAW filter Download PDFInfo
- Publication number
- CN109379056A CN109379056A CN201811462824.5A CN201811462824A CN109379056A CN 109379056 A CN109379056 A CN 109379056A CN 201811462824 A CN201811462824 A CN 201811462824A CN 109379056 A CN109379056 A CN 109379056A
- Authority
- CN
- China
- Prior art keywords
- via hole
- metal pad
- ceramic shell
- metal
- metal 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.)
- Pending
Links
- 229910052751 metal Inorganic materials 0.000 claims abstract description 85
- 239000002184 metal Substances 0.000 claims abstract description 85
- 239000000919 ceramic Substances 0.000 claims abstract description 33
- 239000000463 material Substances 0.000 claims description 11
- 229910052782 aluminium Inorganic materials 0.000 claims description 5
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 5
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims description 5
- 239000010931 gold Substances 0.000 claims description 5
- 229910052737 gold Inorganic materials 0.000 claims description 5
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims description 5
- 229910052721 tungsten Inorganic materials 0.000 claims description 5
- 239000010937 tungsten Substances 0.000 claims description 5
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical group [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 4
- 229910052802 copper Inorganic materials 0.000 claims description 4
- 239000010949 copper Substances 0.000 claims description 4
- 229910000831 Steel Inorganic materials 0.000 claims description 3
- 239000010959 steel Substances 0.000 claims description 3
- 239000004411 aluminium Substances 0.000 claims description 2
- 239000004020 conductor Substances 0.000 claims description 2
- 238000004021 metal welding Methods 0.000 claims description 2
- 239000011799 hole material Substances 0.000 claims 11
- 238000001914 filtration Methods 0.000 abstract description 5
- 238000010586 diagram Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 229910003327 LiNbO3 Inorganic materials 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 235000012239 silicon dioxide Nutrition 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 229910012463 LiTaO3 Inorganic materials 0.000 description 1
- JRPBQTZRNDNNOP-UHFFFAOYSA-N barium titanate Chemical compound [Ba+2].[Ba+2].[O-][Ti]([O-])([O-])[O-] JRPBQTZRNDNNOP-UHFFFAOYSA-N 0.000 description 1
- 229910002113 barium titanate Inorganic materials 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 229910052681 coesite Inorganic materials 0.000 description 1
- 229910052906 cristobalite Inorganic materials 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000001934 delay Effects 0.000 description 1
- GQYHUHYESMUTHG-UHFFFAOYSA-N lithium niobate Chemical compound [Li+].[O-][Nb](=O)=O GQYHUHYESMUTHG-UHFFFAOYSA-N 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000008520 organization Effects 0.000 description 1
- 230000000644 propagated effect Effects 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 229910052682 stishovite Inorganic materials 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 229910052905 tridymite Inorganic materials 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic elements; Electromechanical resonators
- H03H9/02—Details
- H03H9/02535—Details of surface acoustic wave devices
- H03H9/02818—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 elements; Electromechanical resonators
- H03H9/02—Details
- H03H9/02535—Details of surface acoustic wave devices
Landscapes
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)
Abstract
A kind of SAW filter, its rejection ability that can greatly increase remote out of band signal, meet the requirement of the Out-of-band rejection ratio of client's centering high band, it is greatly improved the propagation efficiency and filtering performance of useful signal, it includes ceramic shell, ceramic shell edge is provided with metal pad, the intermediate position of ceramic shell is provided with filter chip, metal pad includes 12, respectively metal pad one is to metal pad 12, wherein eight are respectively arranged with via hole between metal pad and ceramic shell, metal layer is coated in each via hole, ground metal layer connection on metal layer and ceramic shell in each via hole.
Description
Technical field
The present invention relates to SAW filter technical field, specially a kind of SAW filter.
Background technique
SAW filter is that using quartz, lithium niobate, barium titanate crystal there is the property of piezoelectric effect to be made into, by
It is only propagated in plane of crystal in its sound wave, therefore referred to as SAW filter, effect is identical as the effect of common filter,
It is that the signal of needs is allowed to pass through, unwanted signal is filtered out.Propagation efficiency of the SAW filter to useful signal
Mainly pass through passband internal loss, Out-of-band rejection than performances such as, the standing-wave ratio of input/output terminal and group delays with its filtering performance
Index judged, when frequency is 1000MHz ~ 6000MHz, SAW filter commonly used in the prior art to remote band outside
The rejection ability of signal is poor, and the lowest absolute value of Out-of-band rejection ratio is 5dB, but the Out-of-band rejection of customer demand is than minimum
Absolute value need to be more than or equal to 8dB, and therefore, SAW filter in the prior art is unable to satisfy client for high performance filter
Requirement.
Summary of the invention
It is poor for rejection ability of the SAW filter existing in the prior art to remote out of band signal, it is unable to satisfy
The technical issues of client is to filter high performance requirements, the present invention provides a kind of SAW filters, can greatly increase
The rejection ability of remote out of band signal, meets requirement of the client to filter Out-of-band rejection ratio, is greatly improved the biography of useful signal
Broadcast efficiency and filtering performance.
A kind of SAW filter comprising ceramic shell, the ceramic shell edge are provided with metal pad,
The intermediate position of the ceramic shell is provided with filter chip, and the bottom end of the ceramic shell is provided with ground metal layer, institute
It states and is connected between metal pad and the ground metal layer by via hole, led between the metal pad and the filter chip
Cross bonding wire connection, which is characterized in that the metal pad includes 12, is sequentially named as metal pad one respectively to metal welding
Disk 12, selection are wherein respectively arranged with the via hole between eight metal pads and the ceramic shell, each described
Metal layer is coated in via hole, the metal layer in each via hole is connect with the ground metal layer;Selection wherein eight
A metal pad is connect by the bonding wire with the filter chip.
It is further characterized by,
Metal layer in the material of the metal pad and the via hole is conductive material;
The material of the metal pad is aluminium or tungsten;
The material of metal layer in the via hole is tungsten;
The material of the ground metal layer is copper;
The metal pad one to metal pad eight passes through the metal layer on the via hole and connecing on the ceramic shell respectively
The connection of ground metal layer, the metal pad two, three, five, six, eight, nine, 11,12 pass through bonding wire and the filter respectively
Chip connection;
The bonding wire is aluminum steel;
The filter chip be LiNbO3 filter chip, LiTaO3 filter chip, SiO2 filter chip it is any one
Kind.
The aperture of eight via holes is equal;
The surface area of each metal pad is consistent;
The aperture of the via hole is 0.08mm, and the height of the via hole is 0.15mm, the gold being connected with the via hole
The length for belonging to pad is 0.3mm, width 0.2mm, with a thickness of 0.01mm;
Cover board is provided on the top end face of the ceramic shell;
It is arranged fluted on the outer end face of the ceramic shell, is coated with metal layer in the groove, the material of the metal layer
Matter is gold.
Using above structure of the invention, by 12 metal pads wherein eight metal pads and ceramic shell it
Between via hole is respectively set, and metal layer is coated in each via hole, the ground connection gold on the metal layer and ceramic shell in each via hole
Belong to layer connection, significantly increases the grounded capacity of parallel signal, improve the rejection ability of the remote out of band signal of filter, the filtering
8dB of the Out-of-band rejection of device than having reached customer demand, meets requirement of the client for high performance filter.
Detailed description of the invention
Fig. 1 is the structural schematic diagram overlooked when cover board is not added in the present invention;
Fig. 2 is the structural schematic diagram that the present invention overlooks;
Fig. 3 is the structural schematic diagram of main view of the present invention;
Fig. 4 is that the present invention improves front and back Out-of-band rejection than change curve varying with frequency.
Specific embodiment
See Fig. 1, Fig. 2, Fig. 3, a kind of SAW filter comprising ceramic shell 13, ceramic shell edge are set
It is equipped with metal pad 20, the intermediate position of ceramic shell 13 is provided with filter chip 14, and filter chip 14 is LiNbO3 filter
Wave device chip is provided with via hole 15, metal pad and filtering between the ground metal layer 16 on metal pad and ceramic shell 13
It is connected between device chip 14 by bonding wire, the quantity of metal pad, via hole 15 and bonding wire 17 is according to client couple on ceramic shell 13
Filter inhibits the performance requirement flexible choice of ratio, optimum organization configuration;
In the present embodiment, metal pad includes 12, respectively metal pad 1 to metal pad 12, wherein eight
It is respectively arranged with via hole 15 between metal pad and ceramic shell 13, is coated with metal layer 21, metal pad in each via hole 15
One 1 are connected by the ground metal layer 16 of metal layer 21 and 13 bottom end of ceramic shell inside via hole 15 respectively to metal pad 88
It connects, the material of metal pad 20 and via hole inner metal layer 21 is tungsten, further improves the grounded capacity of parallel signal, is grounded
The material of metal layer 16 is copper;
Metal pad 22,33,55,66,88,99,11,12 passes through bonding wire 17 and filter chip 14 respectively
Connection, bonding wire 17 are aluminum steel;
The aperture of eight via holes 15 is equal, and the aperture of via hole 15 is 0.08mm, and the height of via hole 15 is 0.15mm, with via hole 15
The length for each metal pad 20 being connected is 0.3mm, width 0.2mm, with a thickness of 0.01mm;The top end of ceramic shell 13
It is provided with cover board 19 on face, several grooves 18 are provided on the side end face of ceramic shell 13, are coated with metal layer in groove 18,
The material of the metal layer of coating is copper in groove 18, the electric conductivity of the present apparatus is further increased, to improve useful signal
By efficiency, the metal layer in groove 18 is connect with ground metal layer 16, and ceramic shell 13 is rectangular parallelepiped structure in the present embodiment,
The position that the adjacent both sides of the face of ceramic shell 13 are connected is respectively set fluted 18, the metal layer of groove 18 and its inside
The setting of gold further improves the grounded capacity of the present apparatus, thus further improve present apparatus signal by efficiency and whole
Body performance.
That the specific working principle is as follows is described for it: applying the present invention to base station, base station is link signal transmitting terminal and receives
The filter is applied to the signal between base station chaining signal transmitting terminal and receiving end and filtered, actually answered by the terminal at end
In, according to the transmission principle of SAW filter in the prior art, the bigger explanation of the absolute value of Out-of-band rejection ratio effectively letter
Number overall performance higher by efficiency, filter it is better.The quantity of metal pad, via hole and bonding wire is optimized first
Secondly combination measures this kind combination using vector network analyzer to meet requirement of the client for Out-of-band rejection than performance
Under Out-of-band rejection ratio, again using HFSS software to this kind combination under Out-of-band rejection ratio emulate, draw out imitative
True test waveform figure;Customer requirement is when the working frequency of filter is 1000MHz ~ 6000MHz in the embodiment, with outer suppression
System need to be more than or equal to 8dB than absolute value, and eight via holes 15 are arranged in the present invention altogether, when the working frequency range of SAW filter is
When 1000MHz ~ 6000MHz, show that the band of the device is outer using vector network analyzer commonly used in the prior art measurement analysis
Inhibit ratio, i.e. the decline difference of passband edge and central point, this group of Out-of-band rejection ratio is emulated using HFSS software
Operation, emulation testing waveform diagram is as shown in figure 4, horizontal axis frequency indicates the working frequency of filter, vertical pivot in Fig. 4
Magnitude indicates that the performance rate of Out-of-band rejection ratio, curve A indicate that SAW filter work exists in the prior art
When 1000MHz ~ 6000MHz frequency range, Out-of-band rejection is than waveform diagram varying with frequency, and Out-of-band rejection is than minimum 5dB, curve B
Indicate that filter of the invention works in the frequency range, Out-of-band rejection is than curve graph varying with frequency, Out-of-band rejection ratio
Minimum 8dB is higher than 5dB in the prior art, meets client to the high performance demand of filter, inhibits remote out of band signal
Ability greatly promotes, in addition, the promotion of remote out of band signal rejection ability, can be such that the service life of product greatly improves, thus into
One step enhances the competitiveness of product.
Claims (8)
1. a kind of SAW filter comprising ceramic shell, the ceramic shell edge are provided with metal pad, institute
The intermediate position for stating ceramic shell is provided with filter chip, and the bottom end of the ceramic shell is provided with ground metal layer, described
It is connected between metal pad and the ground metal layer by via hole, is passed through between the metal pad and the filter chip
Bonding wire connection, which is characterized in that the metal pad includes 12, respectively metal pad one to metal pad 12,
In the via hole is respectively arranged between eight metal pads and the ceramic shell, be coated with gold in each via hole
Belong to layer, the metal layer in each via hole is connect with the ground metal layer;Wherein eight metal pads pass through
The bonding wire is connect with the filter chip.
2. a kind of SAW filter according to claim 1, which is characterized in that the metal pad, the via hole
The material of interior metal layer is conductive material, and the material of the metal pad is aluminium or tungsten, the metal layer in the via hole
Material is tungsten, and the material of the ground metal layer is copper.
3. a kind of SAW filter according to claim 2, which is characterized in that the metal pad one to metal welding
Disk eight is connect by the metal layer on the via hole with the ground metal layer on the ceramic shell respectively, the metal pad
Two, it three, five, six, eight, nine, 11,12 is connect respectively by the bonding wire with the filter chip.
4. a kind of SAW filter according to claim 3, which is characterized in that the bonding wire is aluminum steel.
5. according to claim 1 or a kind of 4 described in any item SAW filters, which is characterized in that eight via holes
Aperture it is equal.
6. a kind of SAW filter according to claim 5, which is characterized in that the surface area of each metal pad
Unanimously.
7. a kind of SAW filter according to claim 6, which is characterized in that the aperture of the via hole is
0.08mm, the height of the via hole are 0.15mm, and the length for the metal pad being connected with the via hole is 0.3mm, wide
Degree is 0.2mm, with a thickness of 0.01mm.
8. according to claim 1 or a kind of 7 described in any item SAW filters, which is characterized in that the ceramic shell
Top end face on be provided with cover board.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
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CN201811462824.5A CN109379056A (en) | 2018-12-03 | 2018-12-03 | A kind of SAW filter |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201811462824.5A CN109379056A (en) | 2018-12-03 | 2018-12-03 | A kind of SAW filter |
Publications (1)
Publication Number | Publication Date |
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CN109379056A true CN109379056A (en) | 2019-02-22 |
Family
ID=65375094
Family Applications (1)
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CN201811462824.5A Pending CN109379056A (en) | 2018-12-03 | 2018-12-03 | A kind of SAW filter |
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CN207166467U (en) * | 2017-09-07 | 2018-03-30 | 全讯射频科技(无锡)有限公司 | A kind of wave filter for car key |
CN108352826A (en) * | 2015-11-27 | 2018-07-31 | 株式会社村田制作所 | Filter apparatus |
CN209250589U (en) * | 2018-12-03 | 2019-08-13 | 全讯射频科技(无锡)有限公司 | A kind of SAW filter |
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2018
- 2018-12-03 CN CN201811462824.5A patent/CN109379056A/en active Pending
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CN1691501A (en) * | 2004-04-27 | 2005-11-02 | 富士通媒体部品株式会社 | Antenna duplexers and electronics |
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CN105655674A (en) * | 2016-03-24 | 2016-06-08 | 成都九洲迪飞科技有限责任公司 | Zero point adjustable microstrip filter |
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