Acoustic wave device and its wafer-level packaging method
Technical field
The present invention relates to semiconductor field, in particular to a kind of acoustic wave device and its wafer-level packaging method.
Background technique
The mode supported with mobile radio system and frequency range are continuously increased, Current wireless communication mobile terminal
RF front end structure also become to become increasingly complex.
Fig. 1 is one and supports the communication mobile terminal of multiple frequency ranges in 2G, 3G, 4G multi-mode and each mode
RF front end structure.108 be the RF transceiver chip of mobile terminal, is responsible for the radiofrequency signal for generating baseband chip and sends
It is handled to corresponding power amplifier chip and to the radiofrequency signal received.107,105,106 be 2G power respectively
Amplifier chip, 3G/4G single-frequency power amplifier chip, 3G/4G multimode multi-frequency power amplifier chip, these chips all to from
The radiofrequency signal come transmitted by RF transceiver 108 carries out power amplification.104 be a series of duplexer chips, each FDD
The frequency range of mode requires a corresponding duplexer chip to be emitted and be received the separation of signal.103 be one integrated
The hilted broadsword of low-pass filter throws radio-frequency antenna switch chip more, for by the output signals of multiple radio-frequency power amplifiers and
The radiofrequency signal that multichannel is received from antenna carries out branch separation, so that multiple radio-frequency transmissions accesses and multiple radio frequency receptions are logical
Road can share the same primary antenna 101.Hilted broadsword is thrown more usually all integrates two low-pass filtering in radio-frequency antenna switch chip 103
Device is respectively used to filter out the harmonic wave and 2G low-frequency range (820- of 2G high band (1710-1910MHz) radio-frequency power amplifier
920MHz) the harmonic wave of radio-frequency power amplifier.102, which are one, is connected to primary antenna 101 and multimode multi-frequency radio frequency duplexer core
Antenna match tuning chip between piece 103, for being adjusted to ensure that good antenna resistance in real time to Antenna Impedance Matching
Anti- matching.111 be a diversity radio-frequency antenna switch chip, for the radiofrequency signal received from diversity antenna 112 into
The separation of row branch.110 be a series of filter chips, each road radio frequency for exporting to diversity radio-frequency antenna switch chip 111
Signal is filtered, and output signal is sent to the phase of RF transceiver chip 108 further through receiving path switch chip 109
Answer receiving port.
As seen from Figure 1, as the growth of multimode multi-frequency radio frequency front-end module demand, duplexer and filter will become
Main device.Filter segment mainly uses discrete inductance, capacitor element to realize to realize, or using IPD technique;Duplex
Device is then mainly realized using the acoustic wave devices such as surface acoustic wave (SAW), bulk acoustic wave (BAW), film bulk acoustic (BAW).Surface acoustic wave
It is that sound wave is propagated in body surface finite depth, is propagated along solid and Air Interface, meanwhile, surface acoustic wave is a kind of energy
Amount concentrates on the elastic wave of dielectric surface propagation;What bulk acoustic wave and film bulk acoustic utilized is that bulk acoustic wave signal is passed in different medium
Sowing time reflects in the boundary place of two electrodes and air, and bulk acoustic wave and film bulk acoustic and substrate surface form a sky
It is intracavitary to be limited in piezoelectric vibration by air cavity for sound wave.It can be seen that for surface acoustic wave, bulk acoustic wave and film bulk acoustic are all needed
A closed cavity is formed, for limiting the propagation path of sound wave at the interface with substrate.Acoustic wave device production
The advantages that filter and duplexer, insertion loss is small, and Out-of-band rejection is good, is widely used in wireless communication field.The side of encapsulation
Formula is broadly divided into: Metal Packaging, Plastic Package, surface mount packages.Their a minimum of two parts compositions, that is, the substrate encapsulated and upper
Lid.A small amount of binder is coated in substrate, and then chip is attached to above.By curing process, chip is firmly attached to
In substrate.
Metal Packaging: it is made of the metallic substrates comprising insulation and grounding pin and metal cap.It is put into pulse point
Sealing machine carries out sealing cap, obtains the good finished product of leakproofness.It is good that the common technique of Metal Packaging can produce leakproofness
Good high frequency filter, simultaneously because mechanical properties strength is high, chip that can be big with encapsulation volume.
Plastic Package: being made of slot and cap two parts, and chip is connected on lead frame by bonding line, the lead of metal
Frame protrudes into slot from one side, and finally two parts are bonded together.The main advantage of this encapsulation technology is at low cost.
Surface mount packages: ceramic SMD (Surface Mounted Device: surface mount device), using substrate and hat shape
Upper cover.Two kinds of technologies are used according to different purposes: for high-frequency element and the high device of high frequency accuracy, being encapsulated using metal layer;
For low frequency device, encapsulated using plasticity sound-absorbing material.
Fig. 2 is to encapsulate schematic diagram using metal layer.Wherein 210 be substrate, and material is based on ceramic LTCC or HTCC technique.
203 be acoustic wave filter or duplexer, by the way of back-off, by copper pillar or tin ball 204,205 and substrate 210
Pad 206,207 connects;And by 210 interior metal cabling of substrate and via hole 208,209 and the pad 211 of 210 bottom of substrate,
212 connections, draw the pin of acoustic wave device.201 be metal cap, is connected by way of welding or gluing with substrate 210;Metal
Polymer material 202 is inserted in gap between cap 201 and acoustic wave device, is used to support metal cap, is prevented metal cap from collapsing.213 are
The airtight cavity formed between acoustic wave device and substrate.
Fig. 3 is to encapsulate schematic diagram using plasticity sound-absorbing material.Wherein 310 be substrate, material be based on ceramic LTCC or
HTCC technique.303 be acoustic wave filter or duplexer, by the way of back-off, by copper pillar or tin ball 304,305 with
Pad 306,307 on 310 connects;And it is welded by 310 interior metal cabling of substrate and via hole 308,309 and 310 bottom of substrate
Disk 311,312 connects, and draws the pin of acoustic wave device.301 be plasticity sound-absorbing material, by way of gluing with 310 phase of substrate
Even;Polymer material 302 is inserted in gap between plasticity sound-absorbing material and acoustic wave device, is used to support plasticity sound-absorbing material, is prevented
Plasticity sound-absorbing material collapses.313 airtight cavities formed between acoustic wave device and substrate.
Fig. 4 is in the prior art based on the schematic diagram of wafer-level packaging, wherein 401 be acoustic wave device, in acoustic wave device
Upper surface makes filter or duplexer.402 be substrate, is made of Si technique.403 be shading ring, passes through welding or glue
Viscous mode links together acoustic wave device 401 and substrate 402, plays the role of shielding and support;Acoustic wave device 401,
Airtight cavity 404 is formd between substrate 402 and shading ring 403, realizes one there must be between acoustic wave device and substrate
A cavity.Meanwhile the input and output pin 405,406 for drawing acoustic wave device is grown in the upper surface of acoustic wave device 401, along screen
The upper surface of substrate is guided in the outer surface for covering ring and substrate, by copper pillar or tin ball 407,408 by the pin of acoustic wave device
It draws.
Metal Packaging and plastic package have the shortcomings that common, have long pin, cause the volume of device too big, very
Hardly possible is integrated with RF front-end module.Based on the surface mount packages of ceramics, although being widely used, complex manufacturing technology, pottery
Ceramic material HTCC and LTCC price, and be difficult to integrate with other techniques, meanwhile, it is existing to be based on wafer-level packaging
Acoustic wave device, there is also technique is relatively difficult to achieve, defect at high cost.Therefore, it is necessary to find a kind of method, size is small, system
Make simple, packaging method that is cheap, and being easy to integrate with other devices.
Summary of the invention
The embodiment of the present invention provides a kind of acoustic wave device and its wafer-level packaging method, passes through the carry out sound directly in substrate
The encapsulation of wave device is, it can be achieved that size is small, and production is simple, sealed in unit that is cheap, and being easily integrated.
According to an aspect of the present invention, a kind of acoustic wave device, including substrate and acoustic wave device are provided, in which:
Substrate is equipped with cavity, and acoustic wave device is in conjunction with the upper surface of substrate, so that cavity becomes airtight chamber;
The lower surface of substrate is equipped with the pin pad of acoustic wave device, the pin pad of acoustic wave device and the pin of acoustic wave device
Pad connection.
In one embodiment, the pin pad of acoustic wave device passes through the pin pad of plating metal cabling and acoustic wave device
Connection.
In one embodiment, the material of plating metal cabling is gold, silver, copper, iron, aluminium, nickel, palladium or tin.
In one embodiment, plating metal cabling prolongs along the substrate side neighbouring with the pin pad of acoustic wave device
It stretches.
In one embodiment, the angle of substrate side and the lower surface of substrate is obtuse angle.
In one embodiment, the lower surface of substrate is identical as the angle of two neighboring substrate side.
In one embodiment, the pin pad of acoustic wave device is aluminium pillar, copper pillar or tin ball.
In one embodiment, acoustic wave device is by adhesive means in conjunction with the upper surface of substrate.
In one embodiment, the pin pad of acoustic wave device and substrate are located on the same surface of acoustic wave device.
In one embodiment, the height of substrate is greater than the depth of cavity.
In one embodiment, acoustic wave device includes surface acoustic wave SAW filter, bulk acoustic wave BAW filter or thin-film body
Sound wave FBAR filter, or including surface acoustic wave SAW duplexer, bulk acoustic wave BAW duplexer or film bulk acoustic FBAR duplex
Device, or include the device using the manufacture of SAW, BAW or FBAR technology.
In one embodiment, above-mentioned acoustic wave device further includes substrate, in which:
Substrate is disposed on the substrate.
In one embodiment, acoustic wave device further includes the electronic device heterogeneous with acoustic wave device being disposed on the substrate,
Wherein:
The pin pad connection corresponding with acoustic wave device of the pin pad of electronic device.
In one embodiment, the pin pad of electronic device is corresponding with acoustic wave device especially by substrate metal cabling
Pin pad connection.
In one embodiment, electronic device includes based on GaAs HBT technique, GaAs pHEMT technique or GaN technique
Radio-frequency power amplifier is based on based on the low-noise amplifier of GaAs pHEMT technique based on the switch of GaAs pHEMT technique
At least one of the filter of IPD technique.
In one embodiment, electronic device include radio-frequency power amplifier driving stage circuit, switching circuit, power supply with
At least one of track and envelope-tracking circuit, DC-DC conversion circuit, analog to digital conversion circuit, D/A converting circuit.
According to another aspect of the present invention, a kind of wafer-level packaging method of acoustic wave device is provided, comprising:
Cavity is set in substrate;
By acoustic wave device in conjunction with the upper surface of substrate, so that cavity becomes airtight chamber;
The pin pad of the pin pad of acoustic wave device and acoustic wave device is connected, wherein the pin pad of acoustic wave device is set
It sets in the lower surface of substrate.
In one embodiment, the pin of the pin pad of acoustic wave device and acoustic wave device is welded by plating metal cabling
Disk connection.
In one embodiment, plating metal cabling prolongs along the substrate side neighbouring with the pin pad of acoustic wave device
It stretches.
In one embodiment, the angle of substrate side and the lower surface of substrate is obtuse angle.
In one embodiment, the lower surface of substrate is identical as the angle of two neighboring substrate side.
In one embodiment, by adhesive means by acoustic wave device in conjunction with the upper surface of substrate.
In one embodiment, the pin pad and substrate of acoustic wave device are arranged on the same surface of acoustic wave device.
In one embodiment, the height of substrate is greater than the depth of cavity.
In one embodiment, substrate is disposed on the substrate.
In one embodiment, the electronic device heterogeneous with acoustic wave device is disposed on the substrate, wherein electronic device
The pin pad connection corresponding with acoustic wave device of pin pad.
In one embodiment, by substrate metal cabling, the pin pad of electronic device is corresponding with acoustic wave device
The connection of pin pad.
By referring to the drawings to the detailed description of exemplary embodiment of the present invention, other feature of the invention and its
Advantage will become apparent.
Detailed description of the invention
In order to more clearly explain the embodiment of the invention or the technical proposal in the existing technology, to embodiment or will show below
There is attached drawing needed in technical description to be briefly described, it should be apparent that, the accompanying drawings in the following description is only this
Some embodiments of invention without any creative labor, may be used also for those of ordinary skill in the art
To obtain other drawings based on these drawings.
Fig. 1 is wireless communication system RF front end structure schematic diagram in the prior art.
Fig. 2 is the schematic diagram that acoustic wave device encapsulates a kind of scheme in the prior art.
Fig. 3 is the schematic diagram that acoustic wave device encapsulates another program in the prior art.
Fig. 4 is the schematic diagram that acoustic wave device encapsulates another aspect in the prior art.
Fig. 5 is the schematic diagram of acoustic wave device one embodiment of the present invention.
Fig. 6 is the schematic diagram of another embodiment of acoustic wave device of the present invention.
Fig. 7 is the schematic diagram of the another embodiment of acoustic wave device of the present invention.
Fig. 8 is the schematic diagram of wafer-level packaging method one embodiment of acoustic wave device of the present invention.
Fig. 9 to Figure 20 is the schematic diagram of wafer-level packaging method one embodiment of acoustic wave device of the present invention.
Specific embodiment
Following will be combined with the drawings in the embodiments of the present invention, and technical solution in the embodiment of the present invention carries out clear, complete
Site preparation description, it is clear that described embodiments are only a part of the embodiments of the present invention, instead of all the embodiments.Below
Description only actually at least one exemplary embodiment be it is illustrative, never as to the present invention and its application or make
Any restrictions.Based on the embodiments of the present invention, those of ordinary skill in the art are not making creative work premise
Under every other embodiment obtained, shall fall within the protection scope of the present invention.
Unless specifically stated otherwise, positioned opposite, the digital table of the component and step that otherwise illustrate in these embodiments
It is not limited the scope of the invention up to formula and numerical value.
Simultaneously, it should be appreciated that for ease of description, the size of various pieces shown in attached drawing is not according to reality
Proportionate relationship draw.
Technology, method and apparatus known to person of ordinary skill in the relevant may be not discussed in detail, but suitable
In the case of, the technology, method and apparatus should be considered as authorizing part of specification.
It is shown here and discuss all examples in, any occurrence should be construed as merely illustratively, without
It is as limitation.Therefore, the other examples of exemplary embodiment can have different values.
It should also be noted that similar label and letter indicate similar terms in following attached drawing, therefore, once a certain Xiang Yi
It is defined in a attached drawing, then in subsequent attached drawing does not need that it is further discussed.
Fig. 5 is the schematic diagram of acoustic wave device one embodiment of the present invention.As shown in figure 5, the acoustic wave device includes substrate 51
With acoustic wave device 52.Wherein:
Substrate 51 is equipped with cavity 511, and acoustic wave device 52 is in conjunction with the upper surface of substrate 51, so that cavity 511 becomes close
Closed chamber room.
Optionally, acoustic wave device 52 is by adhesive means in conjunction with the upper surface of substrate 51.For example, acoustic wave device 52 passes through
Glue 512 is in conjunction with the upper surface of substrate 51.
The lower surface of substrate 51 is equipped with the pin pad 531,532 of acoustic wave device, the pin pad 531,532 of acoustic wave device
It is connect respectively with the pin pad of acoustic wave device 52 521,522.
Optionally, the pin pad 521,522 of acoustic wave device 52 and substrate 51 are located on the same surface of acoustic wave device.
Wherein, substrate 51 is the substrate based on Si process materials.The height of substrate 51 is greater than the depth of cavity 511, cavity
511 depth is more than or equal to 1 μm.It must be protected simultaneously using passivation in the active area of acoustic wave device 52.
Optionally, the pin pad of acoustic wave device is connected by the pin pad of plating metal cabling and acoustic wave device.Example
Such as, the pin pad 531 of acoustic wave device is connect by plating metal cabling 541 with the pin pad 521 of acoustic wave device 52, sound wave
The pin pad 532 of equipment is connect by plating metal cabling 542 with the pin pad 522 of acoustic wave device 52.Wherein, electroplating gold
The material for belonging to cabling can be gold, silver, copper, iron, aluminium, nickel, palladium or tin etc..
In addition, plating metal cabling extends along with the neighbouring substrate side of the pin pad of acoustic wave device, sound wave is set
The pin pad of standby pin pad and acoustic wave device is attached, to draw the pin of acoustic wave device.As shown in figure 5, base
Angle a, b of the lower surface of bottom side and substrate are obtuse angle, that is, are greater than 90 degree and are less than 180 degree.Wherein, angle a, b can be identical,
It can also be different.
Optionally, the pin pad 531,532 of acoustic wave device can be aluminium pillar, copper pillar or tin ball.
Optionally, acoustic wave device 52 may include surface acoustic wave SAW filter, bulk acoustic wave BAW filter or film bulk acoustic
FBAR filter, or including surface acoustic wave SAW duplexer, bulk acoustic wave BAW duplexer or film bulk acoustic FBAR duplexer, or
Person includes the device using the manufacture of SAW, BAW or FBAR technology.
Based on the acoustic wave device that the above embodiment of the present invention provides, by the envelope for carrying out acoustic wave device directly in substrate
Dress is, it can be achieved that size is small, and production is simple, sealed in unit that is cheap, and being easily integrated.
Fig. 6 is the schematic diagram of another embodiment of acoustic wave device of the present invention.As shown in fig. 6, substrate can be placed into substrate 51
On 55.
Multiple substrates combined with acoustic wave device as shown in Figure 5 can be set on substrate 55, it can also be on substrate 55
It is arranged and the heterogeneous electronic device of acoustic wave device.As shown in fig. 6, setting and the heterogeneous electronics device of acoustic wave device 52 on substrate 55
Part 56.Wherein, the pin pad 561 of electronic device 56 pin pad 531 corresponding with acoustic wave device connects.
Optionally, the pin pad 561 of electronic device 56 is corresponding with acoustic wave device especially by substrate metal cabling L1
Pin pad 531 connects.
Optionally, electronic device 56 may include the radio frequency based on GaAs HBT technique, GaAs pHEMT technique or GaN technique
Power amplifier is based on IPD based on the switch of GaAs pHEMT technique based on the low-noise amplifier of GaAs pHEMT technique
At least one of filter of technique.
In addition, electronic device 56 may also include the driving stage circuit of radio-frequency power amplifier, switching circuit, power supply trace and
At least one of envelope-tracking circuit, DC-DC conversion circuit, analog to digital conversion circuit, D/A converting circuit.
Optionally, the electronic device of multiple and different types can be set on substrate 55.As shown in fig. 7, being set on substrate 55
It sets except acoustic wave device 52 and the heterogeneous electronic device 56 of acoustic wave device 52, it is also settable another heterogeneous with acoustic wave device 52
Electronic device 57.Wherein the pin pad 571 of electronic device 57 can be welded by metal routing L2 pin corresponding with acoustic wave device
Disk 532 connects.
That is, multiple acoustic wave devices and related electronic device can be integrated on same substrate 55.
Fig. 8 is the schematic diagram of wafer-level packaging method one embodiment of acoustic wave device of the present invention.Wherein:
Step 801, cavity is set in substrate.
Wherein, the height of substrate is greater than the depth of cavity.
Step 802, by acoustic wave device in conjunction with the upper surface of substrate, so that cavity becomes airtight chamber.
For example, can by adhesive means by acoustic wave device in conjunction with the upper surface of substrate.
Step 803, the pin pad of the pin pad of acoustic wave device and acoustic wave device is connected, wherein the pipe of acoustic wave device
The lower surface of substrate is arranged in foot pad.
Wherein, the pin pad of the pin pad of acoustic wave device and acoustic wave device can be connected by plating metal cabling.
Plating metal cabling extends along with the neighbouring substrate side of the pin pad of acoustic wave device, the lower surface of substrate side and substrate
Angle be obtuse angle.The lower surface of substrate can be identical with the angle of two neighboring substrate side, can also be different.
Optionally, the pin pad and substrate of acoustic wave device are arranged on the same surface of acoustic wave device.
Based on the acoustic wave device wafer-level packaging method that the above embodiment of the present invention provides, by being carried out directly in substrate
The encapsulation of acoustic wave device is, it can be achieved that size is small, and production is simple, sealed in unit that is cheap, and being easily integrated.
Optionally, above-mentioned substrate can be disposed on the substrate.The electronic device setting heterogeneous with acoustic wave device can also be existed
On substrate, the wherein pin pad of electronic device pin pad connection corresponding with acoustic wave device.
Wherein, the pin pad of electronic device pin pad corresponding with acoustic wave device can be connected by substrate metal cabling
It connects.
Wafer-level packaging method of the invention is illustrated below by a specific example.
As shown in Figure 9 and Figure 10, the etch chamber on high resistant Si substrate 91 (usually 8 inches or 12 inches of diameter of wafers)
Body 92.Wherein Fig. 9 is top view, and Figure 10 is side view.
The size and depth of cavity can be set according to actual needs, and the depth of cavity is typically greater than or equal to 1 μm.
As is illustrated by figs. 11 and 12, one layer of glue 93 is brushed on the surface of substrate 91, the thickness of glue generally takes 3 μm less than 10 μm.
Wherein Figure 11 is top view, and Figure 12 is side view.
As shown in Figure 13 and Figure 14, acoustic wave device 94 is attached in substrate 91 using upside-down mounting mode, and by acoustic wave device 94
Pad 941,942 be embedded in glue so that each acoustic wave device is closely connect with substrate 91, to make cavity 92 as closed chamber
Body.Wherein Figure 13 is top view, and Figure 14 is side view.
As shown in Figure 15 and Figure 16, temporary support wafer 95 is connected by way of gluing with the upper surface of acoustic wave device 94
It connects, to provide support carrier for subsequent thinning operation.Wherein Figure 15 is top view, and Figure 16 is side view.
As shown in figure 17, reduction processing is carried out to substrate 91, and substrate 91 is cut to remove the periphery of substrate 91
Region, to expose the pad of acoustic wave device 94.Wherein during carrying out cutting thin and cutting to substrate 91, make substrate 91
Side forms acclive inclined-plane.Wherein, the angle of substrate side and substrate lower surface is obtuse angle, substrate lower surface and two sides
The angle in face can be identical, can also be different.
As shown in figure 18, plating metal cabling 961,962, plating metal are drawn respectively from acoustic wave device pin 941,942
Cabling 961,962 extends to the lower surface of substrate 91, the material of plating metal cabling respectively along the adjacent side of substrate 91
Matter is gold, silver, copper, iron, aluminium, nickel, palladium, tin etc..
As shown in figure 19, in the lower surface of substrate 91, it is convex that aluminium is grown on the surface of plating metal cabling 961,962 respectively
Column, copper pillar or tin ball, to form the pin pad 971,972 of acoustic wave device.
As shown in figure 20, Xie Jianhe removes support wafer 95, and the wafer-level packaging sound wave at this time based on high resistant Si substrate is set
It is standby to be formed.
It should be noted that substrate is usually 8 inches or 12 inches of diameter of high resistant Si in above-mentioned packaging method process
Wafer, resistance value are higher than 1000ohmcm, and acoustic wave device is via in the back-off attachment to substrate of Pick-and-Place process.Face
When support wafer only play the role of temporary support in process flow, usually with the consistent wafer of substrate wafer size.
The present invention, as substrate, carries out the wafer-level packaging of acoustic wave device, realizes ruler by using based on Si process materials
Very little small, production is simple, cheap, and is easily integrated.Meanwhile being connect acoustic wave device with substrate by way of back-off, it is real
Existing acoustic wave device, CMOS tube core and/or SOI tube core, and radio-frequency power amplifier tube core based on GaAs technique is heterogeneous is integrated in
In the same encapsulation, the inexpensive CMOS or SOI tube core based on Si, high integration characteristic and GaAs technique are made full use of
High-breakdown-voltage and high electron mobility characteristic, are widely used in radio-frequency power amplifier.
Description of the invention is given for the purpose of illustration and description, and is not exhaustively or will be of the invention
It is limited to disclosed form.Many modifications and variations are obvious for the ordinary skill in the art.It selects and retouches
It states embodiment and is to more preferably illustrate the principle of the present invention and practical application, and those skilled in the art is enable to manage
The solution present invention is to design various embodiments suitable for specific applications with various modifications.