Surface acoustic wave device with thermally conductive layer

Abstract

To provide a surface acoustic wave device that includes a thermally conductive layer configured to dissipate heat from the device.SOLUTION: A surface acoustic wave device 19 includes a piezoelectric layer (lithium niobate layer 14) and an interdigital transducer (IDT) electrode 16 on the piezoelectric layer. A thermally conductive layer (aluminum nitride layer 12) may be thinner than the piezoelectric layer.SELECTED DRAWING: Figure 1B

Description

[Technical Field]

[0001] Embodiments of the present disclosure relate to surface acoustic wave devices.

[0002] Cross-reference to priority application Any foreign or domestic priority claim identified in the Application Data Sheet filed with this application Any and all applications cited therein are hereby incorporated by reference pursuant to U.S.C. Section 1.57. This application is incorporated herein by reference in its entirety. No. 62 / 522,603, entitled "Surface Acoustic Wave Device," U.S. Pat. This application claims the benefit of priority under Act Section 119(e), the disclosure of which is incorporated herein by reference in its entirety. This application is incorporated herein by reference in its entirety. U.S. Provisional Patent Application No. 62 / 522,588 entitled "Surface Acoustic Wave Filter," U.S. Patent Act No. 60 / 199,999, filed on Oct. 1, 2003, entitled "Patent Citation 119(e)," the disclosure of which is hereby incorporated by reference in its entirety. It can be incorporated. [Background technology]

[0003] A surface acoustic wave filter is a multi-layered surface acoustic wave filter that is configured to filter radio frequency signals. Each resonator may include a surface acoustic wave device. It can be implemented in line frequency electronic systems, e.g., radio frequency front-ends in mobile phones. The filter at the front end may include a surface acoustic wave filter. The filter can be arranged as a duplexer to filter out signals with relatively high power levels. Tarring can generate heat. Summary of the Invention

[0004] Each of the claimed innovations has several aspects, each of which is Not just one of the elements is responsible for the desired attribute. Without further ado, a summary of some prominent features of the present disclosure is provided below.

[0005] One aspect of the present disclosure is a surface acoustic wave device, comprising: a piezoelectric layer; and an interface on the piezoelectric layer. a digital transducer electrode and a surface acoustic wave device configured to dissipate heat; and a thermally conductive layer formed on the piezoelectric layer. The thermally conductive layer is thinner than the piezoelectric layer.

[0006] The thermally conductive layer and the interdigital transducer electrodes may be on opposite sides of the piezoelectric substrate. The thermally conductive layer may also be in physical contact with the piezoelectric layer.

[0007] The thermally conductive layer may be an electrically insulating layer. The thermally conductive layer may be non-toxic. Thermal conductivity of the thermally conductive layer may be at least five times the thermal conductivity of the piezoelectric layer. For example, the thermal conductivity of the thermally conductive layer may be between 23 W / mK and 300 W / mK. It may be in the mK range.

[0008] The thickness of the thermally conductive layer may be less than half the thickness of the piezoelectric layer. It may be larger than a micrometer.

[0009] The thermally conductive layer may comprise aluminum nitride. The thermally conductive layer may comprise silicon nitride. The layer may include at least one of silicon or nitride.

[0010] The piezoelectric layer may include lithium tantalate. The piezoelectric layer may include lithium niobate. The layer thickness may be less than 300 micrometers.

[0011] The surface acoustic wave device further comprises two electrodes covering the interdigital transducer electrodes. It may include silicon oxide.

[0012] One aspect of the present disclosure is a lithium niobate layer and an interdigitated film on the lithium niobate layer. a niobium interdigital transducer electrode and the niobium interdigital transducer electrode; and an aluminum nitride layer on the opposite side of the lithium oxide layer. The aluminum nitride layer is configured to dissipate heat from the surface acoustic wave device. The aluminum niobate layer is thinner than the lithium niobate layer.

[0013] The lithium niobate layer may be at least twice as thick as the aluminum nitride layer. The aluminum nitride layer may have a thickness of at least 6.3 micrometers.

[0014] The aluminum nitride layer may be in physical contact with the lithium niobate layer.

[0015] The surface acoustic wave device further comprises two electrodes covering the interdigital transducer electrodes. It may include a silicon oxide layer.

[0016] Another aspect of the present disclosure is a piezoelectric layer and an interdigital transducer electrode on the piezoelectric layer. and a thermally conductive layer configured to dissipate heat from the surface acoustic wave device. The thermally conductive layer is thinner than the piezoelectric layer. Surface acoustic wave filters are used to transmit radio frequency signals. configured to filter.

[0017] The surface acoustic wave filter may comprise any one or more of the surface acoustic wave devices described herein. It may include any suitable features of the above.

[0018] Another aspect of the present disclosure is a power amplifier configured to provide a radio frequency signal; and a surface acoustic wave filter configured to filter a radio frequency signal. The surface acoustic wave filter is composed of a piezoelectric layer and an interdigital transducer on the piezoelectric layer. a transducer electrode and a thermal conductive member configured to dissipate heat from the surface acoustic wave device; The thermally conductive layer is thinner than the piezoelectric layer.

[0019] The surface acoustic wave filter may be mounted on a single die together with a second surface acoustic wave filter. The thermal conduction layer is formed from the first surface acoustic wave filter in one region of the second surface acoustic wave filter. The heat dissipation device may be configured to dissipate heat.

[0020] The radio frequency module may include a plurality of surface acoustic wave devices and / or a plurality of surface acoustic wave devices as described herein. The surface acoustic wave filter may include one or more suitable features of any of the above.

[0021] Another aspect of the present disclosure is an elastic device configured to provide a filtered radio frequency signal. a surface wave filter and a device configured to transmit the filtered radio frequency signal. The surface acoustic wave filter is a portable device including a piezoelectric layer and an antenna. and a surface acoustic wave device. and a thermally conductive layer configured to:

[0022] The handheld device may include a plurality of surface acoustic wave devices, a plurality of surface acoustic wave filters, and the like, as described herein. The present invention may include any one or more suitable features of a filter, a filter, and / or a plurality of radio frequency modules. do.

[0023] Another aspect of the present disclosure is a first surface acoustic wave filter including a piezoelectric layer, and a second surface acoustic wave filter. a first surface acoustic wave filter in a region corresponding to the second surface acoustic wave filter; and a thermally conductive sheet configured to dissipate heat from the surface acoustic wave filter chip. The thermal conductive sheet is thinner than the piezoelectric layer.

[0024] The first surface acoustic wave filter is used as a transmission filter, and the second surface acoustic wave filter is used as a reception filter. The first surface acoustic wave filter may be a transmission filter of a duplexer, and the second surface acoustic wave filter may be a transmission filter of a duplexer. The surface acoustic wave filter may be a receiving filter of a duplexer. The first surface acoustic wave filter is used as the first transmit filter, and the second surface acoustic wave filter is used as the second transmit filter. Here, the first transmit filter and the second transmit filter are active at different times. The arrangement is as follows:

[0025] The first surface acoustic wave filter includes a first interdigital transducer electrode on a piezoelectric layer. the second acoustic wave filter includes a second interdigital transducer electrode; The thermally conductive layer is disposed opposite to the first interdigital transducer electrode with the piezoelectric layer sandwiched therebetween. Opposite the first interdigital transducer electrode and the second interdigital The thermally conductive sheet extends under the transducer electrodes and is preferably an aluminum nitride layer. The surface acoustic wave filter chip further includes a first interdigital transducer electrode. and a silicon dioxide layer covering the second interdigital transducer electrode.

[0026] The thermal conductive sheet is connected to the interdigital transducer electrodes of the first surface acoustic wave filter. The thermally conductive sheet may be in physical contact with the piezoelectric layer. .

[0027] The thermally conductive sheet may be a non-toxic electrically insulating layer.

[0028] The thickness of the thermally conductive sheet may be less than half the thickness of the piezoelectric layer. It may be greater than 6.3 micrometers.

[0029] The thermally conductive layer may include aluminum nitride. The piezoelectric layer may include lithium niobate. The layer thickness may be less than 300 micrometers.

[0030] The surface acoustic wave filter chip further includes an interdigital transducer for the first surface acoustic wave filter. It may include silicon dioxide covering the transducer electrode.

[0031] Another aspect of the present disclosure is a surface acoustic wave filter including a first surface acoustic wave filter and a second surface acoustic wave filter including a lithium niobate layer. a first elastic surface wave filter in a region corresponding to the second surface wave filter; an aluminum nitride layer configured to dissipate heat from the surface wave filter; The aluminum nitride layer is thinner than the lithium niobate layer.

[0032] The first surface acoustic wave filter is used as a transmission filter, and the second surface acoustic wave filter is used as a reception filter. The first surface acoustic wave filter may be a transmission filter of a duplexer, and the second surface acoustic wave filter may be a transmission filter of a duplexer. The surface acoustic wave filter may be a receiving filter of a duplexer. The first surface acoustic wave filter is used as the first transmit filter, and the second surface acoustic wave filter is used as the second transmit filter. Here, the first transmit filter and the second transmit filter are active at different times. The arrangement is as follows:

[0033] The first surface acoustic wave filter includes a first interdigital transducer electrode on a piezoelectric layer. the second acoustic wave filter includes a second interdigital transducer electrode; The aluminum nitride layer is a piezoelectric layer of the first interdigital transducer electrode. A first interdigital transducer electrode and a second interdigital transducer electrode are located on opposite sides of the - Extends under the digital transducer electrodes.

[0034] The lithium niobate layer may be at least twice as thick as the aluminum nitride layer. The aluminum nitride layer may have a thickness of at least 6.3 micrometers.

[0035] The aluminum nitride layer may be in physical contact with the lithium niobate layer.

[0036] The surface acoustic wave chip further includes an interdigital transducer for the first surface acoustic wave filter. The semiconductor device may include a silicon dioxide layer covering the sensor electrode.

[0037] Another aspect of the present disclosure is a piezoelectric layer, a second surface acoustic wave filter, and a first surface acoustic wave filter. a thermal barrier extending to cover a first region corresponding to the second acoustic wave filter and a second region corresponding to the second acoustic wave filter; and a conductive sheet. The thermally conductive sheet is configured to dissipate heat from the first surface acoustic wave filter covering the second region. The thermally conductive sheet is thinner than the piezoelectric layer.

[0038] The surface acoustic wave filter assembly may include one or more suitable features of the surface acoustic wave chip described herein. may include signs.

[0039] Another aspect of the present disclosure is a power amplifier configured to provide a radio frequency signal and a power amplifier as described herein. and a surface acoustic wave filter assembly including one or more suitable features of the surface acoustic wave filter to be used. It is a radio frequency module.

[0040] Other aspects of the present disclosure include one or more suitable features of the surface acoustic wave devices described herein. A surface acoustic wave filter assembly and a device for transmitting a radio frequency signal from the surface acoustic wave filter assembly and an antenna configured to

[0041] For purposes of summarizing this disclosure, certain aspects, advantages, and novel features of the innovation have been identified herein. It should be understood that not all such advantages may be achieved by any particular implementation. This is not necessarily achieved by the embodiment. Any of the methods taught or suggested herein may be used in a manner that achieves or optimizes one or more of the advantages taught. Other advantages may be realized or practiced without necessarily achieving the other advantages.

[0042] This disclosure is incorporated herein by reference in its entirety. In connection with No. ______ [Attorney Docket No. SKYWRKS.819A2], the entire disclosure The body is incorporated herein by reference. [Brief explanation of the drawings]

[0043] Several embodiments of the present disclosure are described below by way of non-limiting examples with reference to the accompanying drawings, in which: do.

[0044] [Figure 1A] 1 illustrates a cross section of a surface acoustic wave device with a thermally conductive layer on the interdigital transducer electrode side, according to one embodiment. [Figure 1B] 1 illustrates a cross section of a surface acoustic wave device with a thermally conductive layer on the back side, according to one embodiment. [Figure 1C] 1C is a graph illustrating simulated maximum chip temperature versus aluminum nitride thermally conductive layer thickness for several embodiments of the surface acoustic wave device of FIG. 1A and the surface acoustic wave device of FIG. 1B. [Figure 2] 1C is a graph illustrating the relationship between temperature and thickness of an aluminum nitride thermally conductive layer for different piezoelectric layer thicknesses for one embodiment of the surface acoustic wave device of FIG. 1B. [Figure 3-1] 3A and 3B are simulated heat maps of a surface acoustic wave chip without a thermally conductive layer and a surface acoustic wave chip with an aluminum nitride layer on the interdigital transducer electrode side, respectively, according to one embodiment. [Figure 3-2] FIG. 3C is a simulated heat map of a surface acoustic wave chip with an aluminum nitride layer on the backside, according to one embodiment. [Figure 4] Figure 4A is a block diagram of a filter implemented on a separate chip with a thermally conductive layer, Figure 4B is a cross-sectional view of Figure 4A, and Figure 4C illustrates temperature versus position on the chip of Figure 4A. [Figure 5] Figure 5A is a block diagram of filters implemented on separate chips with a common thermally conductive layer, Figure 5B is a cross-sectional view of Figure 5A, and Figure 5C illustrates temperature versus position on the chip of Figure 5A. [Figure 6] Figure 6A is a block diagram of a transmit filter and a receive filter implemented on a single chip with a thermally conductive layer, Figure 6B is a cross-sectional view of Figure 6A, and Figure 6C illustrates temperature versus position on the chip of Figure 6A. [Figure 7] Figure 7A is a block diagram of a transmit filter implemented on a single chip with a thermally conductive layer, Figure 7B is a cross-sectional view of Figure 7A, and Figure 7C illustrates temperature versus position on the chip of Figure 7A. [Figure 8]FIG. 1 is a schematic block diagram of a module including a power amplifier, a switch, and multiple filters according to one or more embodiments. [Figure 9] FIG. 1 is a schematic block diagram of a module including multiple power amplifiers, multiple switches, and multiple filters according to one or more embodiments. [Figure 10] FIG. 1 is a schematic block diagram of a module including multiple power amplifiers, multiple switches, multiple filters according to one or more embodiments, and an antenna switch. [Figure 11] 1 is a schematic block diagram of a wireless communication device including a filter according to one or more embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0045] The following descriptions of certain embodiments represent various descriptions of specific embodiments. The innovations described herein include, for example, numerous other features defined and covered by the claims. In the drawings referred to in this description, the same reference numerals are used It is understood that various reference numbers may indicate identical or functionally similar elements. It is further understood that certain embodiments may be implemented in a manner similar to that shown in the drawings. It may contain more elements than are illustrated on the face and / or portions of the elements illustrated in the drawings. Furthermore, some embodiments may include any combination of features from two or more of the drawings. Any appropriate combination may be incorporated.

[0046] The power handling capability of a surface acoustic wave (SAW) filter device in a given application The present disclosure provides a technology that can improve the power durability of SAW filter devices. The SAW filter is a combination of series surface acoustic wave device resonators and shunt resonators. The surface acoustic wave device may be arranged as a ladder filter including resonators.

[0047] A SAW device is disclosed that includes a thermally conductive layer. The thermally conductive layer has a relatively high thermal conductivity. The thermally conductive layer may have a higher conductivity than the piezoelectric layer of the SAW device. The thermal conductivity of the piezoelectric layer of the SAW device is at least five times higher. The piezoelectric layer is made of a lithium niobate layer with a thermal conductivity of 4.6 W / mK, or a The thermal conductivity of the thermal conductive layer is at least 2. The thermal conductivity of the thermally conductive layer can be, for example, 140 W / mK to 30 can range from 23W / mK to 300W / mK, such as a range of 0W / mK In certain instances, the thermal conductivity of the thermally conductive layer is less than the thermal conductivity of the piezoelectric layer of the SAW device. The thermally conductive layer may be at least 25 times higher, such as a thermally conductive layer containing nitride and / or silicon. For example, an aluminum nitride (AlN) layer, a silicon nitride (SiN) layer or any other suitable thermal It may be a conductive layer.

[0048] The thermally conductive layer can be bonded to the piezoelectric layer. The IDT (Integrated Digital Transducer) electrodes can be in physical contact with the piezoelectric substrate on the opposite side. .

[0049] The thermally conductive layer is thinner than the piezoelectric layer and has a thickness of at least 6.3 micrometers (μm). The thickness of the thermally conductive sheet may be less than the thickness of the piezoelectric layer. The piezoelectric layer is thinner than 300 μm. The piezoelectric layer is made of lithium tantalate (LiTaO). It may be a layer of iTaO3 or a layer of lithium niobate (LiNbO3).

[0050] A single chip may comprise two or more SAW foils containing thermally conductive layers according to the principles and advantages described herein. The filter may include:

[0051] FIG. 1A illustrates a thermally conductive layer on the interdigital transducer electrode side according to one embodiment. 1 illustrates a cross section of a surface acoustic wave device 10 having a nitride semiconductor layer. an aluminum nitride layer 12, a lithium niobate layer 14, an interdigital transducer ( The aluminum nitride layer 12 includes an IDT (internal detent) electrode 16, and a silicon dioxide layer 18. The aluminum nitride layer 12 is a thermally conductive The aluminum nitride layer 12 can function as a heat sink. The aluminum layer 12 may be a polycrystalline aluminum nitride ceramic.

[0052] In FIG. 1A, the aluminum nitride layer 12 is formed on the IDT side of the lithium niobate layer 14. As shown in the example, the aluminum nitride layer 12 is formed in a region above the IDT electrode 16. The surface acoustic wave device is formed so as to cover the lithium niobate layer 14 except for the surface acoustic wave device. The acoustic effect of the aluminum nitride layer 12 on the function of the sensor 10 is avoided and / or substantially reduced. In FIG. 1A, a silicon dioxide layer 18 covers the IDT electrode 16. , which is present between the lithium niobate layer 14 and the aluminum nitride layer 12. IDT electrode 16 The IDT electrode may be made of aluminum. The material of the IDT electrode may be titanium (Ti), gold (A), or u), silver (Ag), copper (Cu), platinum (Pt), tungsten (W), molybdenum (Mo ), ruthenium (Ru), or any suitable combination thereof. For example, I The DT electrode 16 may, in certain applications, comprise aluminum and molybdenum. obtain.

[0053] FIG. 1B is a cross-section of a surface acoustic wave device 19 with a thermally conductive layer on the backside, according to one embodiment. The example surface acoustic wave device 19 includes an aluminum nitride layer 12, a lithium niobate layer 13, and a 1B, the silicon nitride layer 14, the IDT electrode 16, and the silicon dioxide layer 18. The aluminum layer 12 is formed on the side of the lithium niobate layer 14 facing the IDT electrode 16. The side of the lithium niobate layer 14 facing the IDT electrode 16 is a surface acoustic wave device. Illustratively, aluminum nitride layer 12 is a lithium niobate. The aluminum nitride layer 12 is in physical contact with the lithium niobate layer 14. In FIG. 1A, the silicon dioxide layer 18 is bonded to the lithium niobate layer 14. The aluminum nitride layer 14 covers the IDT transducer electrode 16 on the opposite side.

[0054] In FIG. 1B, the thickness of the aluminum nitride layer 12 is labeled as h, and the thickness of the lithium niobate layer 12 is labeled as h. The thickness of the nitrided aluminum layer 14 is labeled as H. As shown in both FIGS. 1A and 1B, The thickness h of the aluminum nitride layer 12 is preferably 0.01 to 0.01 mm. The thickness h of the aluminum nitride layer 12 is smaller than the thickness H of the lithium oxide layer 14. As shown, the thickness is less than half the thickness H of the lithium niobate layer 14.

[0055] The aluminum nitride layer 12 has desirable properties for implementing a thermally conductive layer. Aluminum nitride is electrically insulating. Aluminum nitride is non-toxic. Aluminum nitride is a phase For example, the thermal conductivity of aluminum nitride is about 140 W / ( m·K) (watts per metre per kelvin) to 260W / (m·K). Such thermal conductivity is relatively high for insulating ceramics. The thermal conductivity is more than 25 times that of lithium niobate. The thermal conductivity of the silicon dioxide is approximately 4.6 W / (m·K), and that of lithium tantalate is approximately 4.24 W / (m·K). (m·K). The impurities present at the grain boundaries of aluminum nitride are reduced. This is considered to be one way to increase the thermal conductivity of aluminum nitride.

[0056] The surface acoustic wave device 10 of FIG. 1A and the surface acoustic wave device 19 of FIG. 1B are surface acoustic wave devices. These surface wave devices are arranged to generate surface acoustic waves. In these surface acoustic wave devices, the lithium niobate layer is In some other embodiments, the aluminum nitride layer is a thermally conductive layer. A different piezoelectric layer may be used, such as lithium tantalate. Alternatively or additionally, nitride and / or any other suitable thermally conductive layer, such as a thermally conductive layer comprising silicon. Other suitable thermally conductive layers may also be implemented, such as silicon nitride. It is electrically insulating rather than conductive or semiconductive. The thermally conductive layer may be non-toxic.

[0057] In these surface acoustic wave devices of FIGS. 1A and 1B, the silicon dioxide layer is It is a temperature compensation layer that can make the temperature coefficient of frequency (TCF) of a surface wave device close to zero. In some other embodiments, a different temperature compensating layer may be implemented. The compensating layer may have a positive TCF. Some example temperature compensating layers include tellurium dioxide (T The elastic surface of FIG. 1A includes a silicon oxyfluoride (SiO2) layer or a silicon oxyfluoride (SiOF) layer. Although the surface acoustic wave device 10 and the surface acoustic wave device 19 of FIG. 1B include a silicon dioxide layer, Regardless, a surface acoustic wave device according to any of the principles and advantages described herein may This embodiment can be implemented without the silicon dioxide layer covering the IDT electrodes.

[0058] FIG. 1C illustrates an embodiment of the surface acoustic wave device 10 of FIG. 1A and the surface acoustic wave device 19 of FIG. 1B. Figure 1. Maximum simulated tip temperature vs. thickness of aluminum nitride layer for different geometries. 1B is a graph illustrating the relationship between the thickness of the aluminum nitride layer and the thickness of the aluminum nitride layer. In these simulations, the 0.71×10 3 J / The specific heat capacity (kg·K) of aluminum nitride is 3.26×10 3 kg / m 3 density of was used, and the thermal conductivity of aluminum nitride was 150 W / (m K). Figure 1C As shown in Figure 1, the thickness of the aluminum nitride can have a significant effect on the maximum chip temperature. .

[0059] FIG. 2 shows the results for different piezoelectric layer thicknesses for several embodiments of the surface acoustic wave device 19 of FIG. 1B. 2 is a graph illustrating the relationship between temperature and thickness of an aluminum nitride thermally conductive layer. The curves correspond to different thicknesses H of the lithium niobate layer 14 versus maximum chip temperature. The curves show that the thickness of the surface acoustic wave device 19 is at least 6.3 microns. The thickness of the aluminum nitride layer 12 can significantly improve the thermal performance. can provide desirable thermal performance for lithium niobate layers ranging from 20 μm to 300 μm. Therefore, a relatively thin aluminum nitride layer provides thermal improvement. The curves in FIG. 2 show that the desired thermal improvement occurs at less than half the thickness of the lithium niobate layer. This shows that this can be achieved with an aluminum nitride layer having a thickness of less than 1000 nm. The thickness of the aluminum nitride layer is 1 / 2 the thickness of the lithium niobate layer. The aluminum nitride layer is then heated to a temperature of 1000°C or more, which is a desirable thermal improvement. When the thickness of the substrate is in the range of 6.3 μm to 100 μm, the desired thermal properties are obtained as shown in Figure 2. Improvements will be brought about.

[0060] A relatively thin thermally conductive layer is advantageous in a variety of applications. Compared to thermally conductive layers, a relatively thin thermally conductive layer results in thinner parts and uses less material. The deposition of the thermally conductive layer can be achieved by: This can cause internal stress and / or warpage in the wafer. A relatively thin thermally conductive layer may result in less cracking and / or warping.

[0061] Figure 3A shows a simulated heat map of a surface acoustic wave chip without a thermally conductive layer. The simulated chip is a surface acoustic wave device 10 of FIG. 1A and a surface acoustic wave device 11 of FIG. 1B. It includes a surface acoustic wave device similar to surface acoustic wave device 19, but including an aluminum nitride layer. As shown in the heatmap in Figure 3A, this simulation The maximum chip temperature was 93°C. It supports an input power of 30dBm at a frequency of 785MHz.

[0062] 3B and 3C show a resilient surface with an aluminum nitride layer arranged to dissipate heat. 3B and 3C show heat maps of a simulation of a surface wave device. In this case, the 0.71 x 10 3 The specific heat capacity in J / (kg K) is used , 3.26 x 10 of aluminum nitride 3 kg / m 3 The density of aluminum nitride is used A thermal conductivity of 150 W / (m·K) was used.

[0063] FIG. 3B illustrates an embodiment of an aluminum nitride film on the interdigital transducer electrode side. Figure 3 shows a simulated heat map of a surface acoustic wave chip with a silicon layer. The heat map in B shows the SAW device of FIG. 1A with a 3 μm aluminum nitride layer 12. As shown in the heat map in Figure 3B, The maximum chip temperature was 83°C. Therefore, this simulation corresponds to Figure 3. This represents a maximum chip temperature improvement of 10°C compared to the simulation.

[0064] FIG. 3C illustrates a surface acoustic wave chip with an aluminum nitride layer on the backside, according to one embodiment. The heat map in Figure 3B is a simulated heat map of a 5 μm aluminum nitride film. 3C corresponds to the surface acoustic wave device 19 of FIG. 1B with the aluminum layer 12. As shown in the figure, the maximum chip temperature in this simulation was 73°C. Therefore, this simulation is 2 times slower than the simulation corresponding to Figure 3A. This represents a maximum chip temperature improvement of 0°C.

[0065] The thermally conductive layers described herein can be implemented in a variety of filter assemblies. The surface wave filter assembly includes a surface acoustic wave filter. Examples of filter assemblies and associated graphs are illustrated. The principles and advantages may be implemented together and / or with other features described herein. Although some embodiments may be described with reference to a surface acoustic wave filter, the present invention may also be applied to heat conduction. Any suitable principles and advantages of conductive layers may be used in surface acoustic wave filters and other acoustic wave filters. For example, an acoustic wave filter assembly including The body absorbs heat from the surface acoustic wave filter, the bulk acoustic wave filter, and one of the filters. and a common heat conducting layer arranged to dissipate heat to a region corresponding to the other filter. As another example, one acoustic wave filter assembly may include a surface acoustic wave filter and a Lamb wave filter. and dissipating heat from one of the filters to a region corresponding to the other filter. In another example, the acoustic wave filter assembly may include a common thermally conductive layer. However, a surface acoustic wave filter, a boundary acoustic wave filter, and a filter from one of the filters to the other and a common thermally conductive layer arranged to dissipate heat to an area corresponding to the filter.

[0066] FIG. 4A illustrates a filter including a filter mounted on a separate chip with a separate thermally conductive layer. FIG. 4A is a block diagram of the assembly 40. FIG. 4A shows a first chip 42 including a transmit filter 43; The second chip 44 includes a transmit filter 43 and a receive filter 45. The filter 45 may be a duplexer or other multiplexer (e.g., a quadplexer, hexaplexer, etc.). The transmit filter 43 and the receive filter 45 may be included in a multi-band tuner (e.g., a plexer, an octoplexer, etc.). Each is an elastic surface acoustic wave filter implemented according to the principles and advantages of the surface acoustic wave filter 19 of FIG. In some examples, the transmit filter 43 and / or the receive filter 44 may include a surface wave device. The filter 45 also incorporates any suitable principles and advantages of the surface acoustic wave filter 10 of FIG. 1A, herein. any suitable thermally conductive layer, any suitable piezoelectric layer according to any suitable principles and advantages described; , or any suitable combination thereof.

[0067] 4B is a cross-sectional view of FIG. 4A. The transmit filter 43 filters out relatively high power signals. The relatively high power signal is filtered by the power amplifier, so the heat is relatively high. The receive filter 45 may be a radio frequency signal provided by the receiver. Since the filter 43 filters the signal, the heat generated by the filter 43 is relatively small. The arrows illustrate the flow and magnitude of heat. As shown in FIG. 4B, a relatively large amount of heat However, the IDT electrode 16A of the transmitting filter 43 is connected to the nitride semiconductor via the lithium niobate layer 14A. A relatively small amount of heat flows to the aluminum nitride layer 12A, and a relatively small amount of heat flows to the IDT electrodes of the receive filter 45. 16B, passes through the lithium niobate layer 14B, and flows into the aluminum nitride layer 12B. .

[0068] FIG. 4C illustrates the temperature versus position of the chip of FIG. 4A. This shows that the majority of the heat flow from the first chip 42 to the second chip 44 is in the first chip 42. This is because in the example, the transmitted signal has a higher power than the received signal. The aluminum nitride layer 12A reduces the maximum temperature of the first chip 42 to a temperature lower than a corresponding chip without the aluminum nitride layer. This allows for thermal diffusion, which reduces the temperature.

[0069] FIG. 5A shows a filter assembly including filters mounted on separate chips with a common thermally conductive layer. 4A is a block diagram of the filter assembly 50. The filter assembly 50 is the same as the filter assembly 40 of FIG. Similar to the filter assembly 50, the filter assembly 50 has a common aluminum nitride filter under the tips 42 and 44. The difference is that the system layer 12 is implemented.

[0070] FIG. 5B is a cross-sectional view of FIG. 5A. FIG. 5B includes arrows illustrating heat flow and magnitude. As shown in FIG. 5B, the aluminum nitride layer 12 absorbs heat from the transmit filter 43. This heat can be diffused in one area corresponding to the receiving filter 45. The heat from the transmit filter 43 is dissipated throughout the aluminum nitride layer 12. It may also be diffused into the lithium niobate layer 14B of the receive filter 45.

[0071] FIG. 5C illustrates the temperature versus position of the chip of FIG. 5A. The aluminum nitride layer distributes heat from the transmit filter 43 to the receive filter area. This allows the heat in the transmit filter region to be dissipated more efficiently than in the filter assembly 40 of FIG. Since the temperature can be reduced, the maximum chip temperature can be reduced.

[0072] FIG. 6A shows a single chip 62 with a thermally conductive layer, including a transmit filter 43 and a receive filter 45. 1 is a block diagram of a filter assembly 60 in which the transmit filter 4 is mounted. 3 and receive filter 45 may be a duplexer or other multiplexer (e.g., a quad The filter assembly 60 may be included in a filter assembly such as a filter block, ... , such a duplexer or other multiplexer may be implemented on a single chip. Assembly 60 is similar to filter assembly 50 of FIG. 5A, except that filters 43 and 45 are separate. The difference is that the transmit filter 43 and the receive filter 45 are mounted on a single chip 62. On chip 62, for example, the filter assembly 50 of FIG. 5A may be replaced by a separate chip. This allows the devices to be mounted closer together than if they were mounted in parallel. The heat dissipation in the device can be further improved.

[0073] FIG. 6B is a cross-sectional view of FIG. 6A. FIG. 6B includes arrows illustrating heat flow and magnitude. As shown in FIG. 6B, the aluminum nitride layer 12 dissipates heat from the transmit filter 43. It can be effectively spread over the receive filter area of ​​a single chip 62.

[0074] FIG. 6C illustrates the temperature versus position of the tip of FIG. 6A. Compared to the filter assembly 40, the transmit filter 43 and the 10 shows a significant improvement in maximum chip temperature due to the inclusion of the receive filter 45.

[0075] FIG. 7A shows transmit filters 43A and 44A mounted on a single chip 72 with a thermally conductive layer. 3B. The filter assembly 70 is a block diagram of the filter assembly 70 shown in FIG. 6A. Similar to filter assembly 60, but with a second transmit filter instead of receive filter 45 of FIG. 7A to 7C are different from the above in that a filter 43B is mounted in the same manner as in the above description with reference to FIGS. 6A to 6C. The principle and advantage of this is that multiple filters are provided on a single chip, and each filter is relatively large. Any suitable filter that generates a large amount of heat while other filters generate a relatively small amount of heat. For example, in the filter assembly 70, In this case, one transmit filter is active while the other transmit filter is inactive. The heat from the active transmit filter is spread over an area of ​​the inactive transmit filter. It can be dispersed and dissipated.

[0076] Figure 7B is a cross-sectional view of Figure 7A. Figure 7B includes arrows illustrating heat flow and magnitude. As shown in FIG. 7B, the aluminum nitride layer 12 is the active transmit Heat can be dissipated from filter 43A to the inactive transmit filter area. FIG. 7C illustrates the temperature versus position for the tip 72 of FIG. 7A. Compared to the filter assembly 40, the transmit filter 43 is on a single chip with an aluminum nitride layer. The maximum temperature of chip 72 is significantly improved by including 43A and 43B. The temperature may be comparable to the maximum temperature of the chip 62 in FIG. 6A for a transmitted signal with similar power. .

[0077] The simulation results show that the aluminum nitride layer 12 of the surface acoustic wave device 19 It is shown that a thermally conductive layer with a relatively high thermal conductivity can reduce the maximum chip temperature. Simulation results also showed that the thermal conductivity of the SiO2 layer was 0.01%. (following A to 7C) Multiple surface acoustic wave filters on a single chip can further increase the maximum chip temperature. Such maximum chip temperature improvement can be achieved, for example, by using any of the methods described above. This can be achieved by a relatively thin thermally conductive layer following any suitable principle and advantage.

[0078] 5A-7C show the dissipation of heat due to filtering of relatively high power radio frequency signals. The present invention provides an example of a filter assembly that can dissipate heat from a surface acoustic wave filter. This can be done using any of these filter assemblies. By amplifying the signal, an amplified radio frequency signal can be produced. The surface wave device can filter the amplified radio frequency signal. The heat associated with filtering is dissipated in one area corresponding to the other acoustic wave filters. The heat can be dissipated by using a thermally conductive sheet. For example, the thermally conductive sheet may be thinner than the piezoelectric layer of the surface acoustic wave filter.

[0079] Multiple surface acoustic wave devices can be included in a single filter. A filter including the device may be called a surface acoustic wave filter. The resonators are arranged as series resonators and shunt resonators to form a ladder filter. In some examples, the filter may include a surface acoustic wave resonator and one or more other resonators (e.g., For example, one or more other bulk acoustic wave resonators.

[0080] The filters described herein can be implemented in a variety of package modules. There are several packages in which any suitable principles and advantages of the filters described herein can be implemented. Examples of modules are now described. Figures 8, 9 and 10 show modules according to certain embodiments. FIG. 1 is a schematic block diagram illustrating a package module for processing radio frequency signals. The arrayed modules may be referred to as radio frequency modules.

[0081] FIG. 8 illustrates a power amplifier 82, a switch 84, and a filter 86 according to one or more embodiments. 1 is a schematic block diagram of a module 80 including exemplary elements. The power amplifier 82, the switch 84, and the filter 86 may include a package enclosing the power amplifier 82. The package substrate may be, for example, a laminated substrate. The power amplifier 82 can amplify the radio frequency signal. , which may in certain applications include gallium arsenide bipolar transistors. The switch 84 may be a multi-throw radio frequency switch. The output may be electrically coupled to a selected filter of filters 86. 86 may include any suitable number of surface acoustic wave filters and / or other acoustic wave filters. One or more of the surface acoustic wave filters of filter 86 may be a surface acoustic wave device as described herein. The present invention may be implemented in accordance with any suitable principles and advantages.

[0082] FIG. 9 illustrates a power amplifier 82A and 82B, switches 84A and 84B, and one or more implementations of 1 is a schematic block diagram of a module 90 including a filter 86' according to the present invention. Module 90 is similar to module 80 of FIG. 8, except that module 90 includes an additional power amplifier 8 2B and an additional switch 84B, and a filter 86' connects the plurality of power amplifiers 82A and 8 2B. The signal paths may be in different frequency bands and / or different operating modes (e.g., different power modes, different The signaling mode may be associated with a different signaling mode.

[0083] FIG. 10 shows a circuit diagram of power amplifiers 82A and 82B, switches 84A and 84B, and one or more A module including filters 86A and 86B according to an embodiment and an antenna switch 102 9 is a schematic block diagram of module 100. Module 100 is similar to module 90 of FIG. However, the module 100 is configured to transmit the signal from the filter 86A or the filter 86B to the antenna node. 1. The antenna differs in that it includes an antenna switch 102 arranged to selectively couple a signal to Filters 86A and 86B may correspond to filter 86' of FIG.

[0084] FIG. 11 is a schematic diagram of a wireless communication device 110 including a filter 86 according to one or more embodiments. 1 is a block diagram of a wireless communication device 110. The wireless communication device 110 may be any suitable wireless communication device. For example, the wireless communication device 110 may be a mobile phone such as a smartphone. As illustrated, the wireless communication device 110 includes an antenna 111, an RF front end 112, an RF transceiver 114, a processor 115 and a memory 116. 1 can transmit an RF signal provided by the RF front end 112. Antenna 111 provides the received RF signal to RF front end 112 for processing. Possible.

[0085] The RF front end 112 may include one or more power amplifiers, one or more low noise amplifiers, one or more RF switch, one or more receive filters, one or more transmit filters, one or more duplexers , or any suitable combination thereof. The present invention is capable of transmitting and receiving RF signals associated with any suitable communication standard. Surface acoustic wave device and / or filter assembly and / or radio frequency module disclosed Any of these may be implemented in the RF front end 112.

[0086] The RF transceiver 114 transmits the RF signal to the RF front end for amplification and / or other processing. The RF transceiver 114 can also be provided to the RF front end 112. The RF transceiver 114 can process RF signals provided by the 12 low noise amplifiers. In communication with the processor 115, the processor 115 may be a baseband processor. The processor 115 may perform any suitable baseband processing functions for the wireless communication device 110. The memory 116 is accessible to the processor 115. The library 116 may store any suitable data for the wireless communication device 110. do.

[0087] Any of the principles and advantages described herein may be implemented in any of the systems, modules, and flash memory devices described above. Other systems, modules, including but not limited to filters, multiplexers, wireless communication devices and methods Tools, chips, surface acoustic wave devices, filters, duplexers, multiplexers, wireless communication The elements and operations of the various embodiments described above may be applied to communication devices and methods. , can be combined to provide further embodiments. Both of these advantages are in the frequency range of about 30 kHz to 300 GHz, e.g., about 450 MHz. Implemented in conjunction with radio frequency circuitry configured to process signals in the ~6GHz range For example, any of the filters described herein may be used in a frequency range of about 30k. Hz to 300 GHz, for example, filtering signals in the range of about 450 MHz to 6 GHz. It is possible.

[0088] Aspects of the present disclosure can be implemented in a variety of electronic devices. Examples include consumer electronic products, chips and / or packaged radio frequency modules. Components for consumer electronic products, electronic test equipment, uplink wireless communication devices, personal electronics Examples of consumer electronic products include, but are not limited to, network communication devices, etc. Can be worn on mobile phones such as smartphones, smart watches, or earpieces functional computing devices, telephones, televisions, computer monitors, computers, Routers, modems, handheld computers, laptop computers, tablet computers computers, personal digital assistants (PDAs), and automotive electronic systems. Vehicle electronic systems, microwave ovens, refrigerators, stereo systems, digital music players, This may include cameras such as digital cameras, portable memory chips, consumer electronics, etc. Furthermore, the electronic device may include, but is not limited to, an unfinished product.

[0089] Furthermore, the following are among others: "can," "might," "may," "might," "even Conditional language such as "if," "like," etc., used herein generally refers to situations where the Unless stated or understood otherwise by the context of use, a given embodiment that one embodiment includes certain features, elements and / or conditions while other embodiments do not. The term "coupled" as generally used herein means directly connected to one another. refers to two or more elements that can either be joined together or connected via one or more intermediate elements. Similarly, the term "connected" as generally used herein refers to directly connected or to one or more It refers to two or more elements that may be either connected or disconnected through an intermediate element. The terms "here," "above," "below," and words of similar import, when used in this application, , refers to this application as a whole and not to any specific portion of this application.

[0090] Although certain embodiments have been described, these embodiments are presented by way of example only. It is not intended to limit the scope of the present disclosure. The novel devices, chips, methods, apparatus, and systems may be embodied in various other forms. Furthermore, various omissions and variations in the methods, apparatus and system configurations described herein may be used. Changes may be made without departing from the scope of this disclosure. For example, the circuit blocks described herein may be Blocks can be deleted, moved, added, subdivided, combined, and / or modified. Each of the circuit blocks can be implemented in a variety of different ways. and equivalents thereof, any such forms or modifications falling within the scope and spirit of the present disclosure. is intended to cover.

Claims

1. A surface acoustic wave device, comprising: a piezoelectric layer; interdigital transducer electrodes on the piezoelectric layer; a thermally conductive layer configured to dissipate heat from the surface acoustic wave device; Including, the thermally conductive layer is thinner than the piezoelectric layer; The surface acoustic wave device is configured to generate a surface acoustic wave.

2. The thermally conductive layer and the interdigital transducer electrodes are disposed on opposite sides of the piezoelectric substrate. The surface acoustic wave device of claim 1 .

3. 3. The surface acoustic wave device of claim 2, wherein the thermally conductive layer is in physical contact with the piezoelectric layer.

4. 2. The surface acoustic wave device according to claim 1, wherein the thermally conductive layer is an electrically insulating layer.

5. 2. The elastic modulus of claim 1, wherein the thermal conductivity of the thermally conductive layer is at least five times the thermal conductivity of the piezoelectric layer. Surface wave devices.

6. 2. The elastic body of claim 1, wherein the thermal conductivity of the thermally conductive layer is in the range of 23 W / mK to 300 W / mK. Surface wave devices.

7. 2. The surface acoustic wave device of claim 1, wherein the thickness of the thermally conductive layer is less than half the thickness of the piezoelectric layer. vinegar.

8. 2. The surface acoustic wave device of claim 1, wherein the thickness of the thermally conductive layer is greater than 6.3 micrometers. Chair.

9. 2. The surface acoustic wave device of claim 1, wherein the thermally conductive layer comprises aluminum nitride.

10. 2. The surface acoustic wave device of claim 1, wherein the piezoelectric layer comprises lithium niobate.

11. 2. The surface acoustic wave device of claim 1, wherein the thickness of the piezoelectric layer is less than 300 micrometers. 。

12. 10. The method of claim 1 further comprising: covering the interdigital transducer electrodes with silicon dioxide. Surface acoustic wave devices.

13. 1. A radio frequency module, comprising: a power amplifier configured to provide a radio frequency signal; a surface acoustic wave filter configured to filter the radio frequency signal; Including, The surface acoustic wave filter comprises: a piezoelectric layer; interdigital transducer electrodes on the piezoelectric layer; a thermally conductive layer configured to dissipate heat from the surface acoustic wave device; Including, The radio frequency module, wherein the thermally conductive layer is thinner than the piezoelectric layer.

14. the surface acoustic wave filter and the second surface acoustic wave filter are mounted on a single die; The heat conduction layer transfers heat from the first surface acoustic wave filter to the second surface acoustic wave filter.

14. The radio frequency module of claim 13 configured to dissipate radiation over an area.

15. a radio frequency switch is provided in a signal path between the power amplifier and the surface acoustic wave filter; 14. The radio frequency module of claim 13, comprising:

16. 14. The thermal conductivity of the thermally conductive layer is at least 25 times the thermal conductivity of the piezoelectric layer. -Radio frequency module.

17. 14. The method of claim 13, wherein the thermal conductivity of the thermally conductive layer is in the range of 140 W / mK to 300 W / mK. Radio frequency module.

18. the thickness of the thermally conductive layer is greater than 6.3 micrometers; 14. The radio frequency module of claim 13, wherein the thickness of the piezoelectric layer is less than 300 micrometers. Rule.

19. 1. A wireless communication device, comprising: a surface acoustic wave filter configured to provide a filtered radio frequency signal; an antenna configured to transmit the filtered radio frequency signal; Including, The surface acoustic wave filter comprises: a piezoelectric layer; interdigital transducer electrodes on the piezoelectric layer; a thermally conductive layer configured to dissipate heat from the surface acoustic wave device; Including, A wireless communication device, wherein the thermally conductive layer is thinner than the piezoelectric layer.

20. and a transceiver in communication with the radio frequency front end including the surface acoustic wave filter.

20. The wireless communication device of claim 19.

21. A surface acoustic wave filter assembly, a first surface acoustic wave filter including a piezoelectric layer; a second surface acoustic wave filter; Heat from the first surface acoustic wave filter is transferred to a second surface acoustic wave filter. a thermally conductive sheet configured to dissipate heat in the region; Including, The surface acoustic wave filter assembly has a thermally conductive sheet that is thinner than the piezoelectric layer.

22. the first surface acoustic wave filter is a transmission filter, 22. The surface acoustic wave filter set according to claim 21, wherein the second surface acoustic wave filter is a receiving filter. Attached body.

23. the first surface acoustic wave filter is a transmission filter of a duplexer; 22. The surface acoustic wave filter of claim 21, wherein the second surface acoustic wave filter is a receiving filter of the duplexer. Surface acoustic wave filter assembly.

24. the first surface acoustic wave filter is a first transmission filter, the second surface acoustic wave filter is a second transmit filter, The first transmit filter and the second transmit filter are active at different times.

22. The surface acoustic wave filter assembly of claim 21, wherein the surface acoustic wave filter assembly is arranged as follows:

25. The first surface acoustic wave filter and the second surface acoustic wave filter are included on a single chip.

22. The surface acoustic wave filter assembly according to claim 21,

26. The thermally conductive sheet and the interdigital transducer of the first surface acoustic wave filter 22. The surface acoustic wave filter assembly according to claim 21, wherein the electrodes are located on opposite sides of the piezoelectric layer.

27. The thermally conductive layer is formed on the second interdigital transducer of the second surface acoustic wave filter. a first interdigital transducer electrode and a second interdigital transducer electrode extending below the first interdigital transducer electrode; The surface acoustic wave filter assembly of claim 26.

28. 22. The surface acoustic wave filter assembly of claim 21, wherein the thermally conductive sheet is in physical contact with the piezoelectric layer. body.

29. 22. The surface acoustic wave filter assembly according to claim 21, wherein the thermally conductive sheet is an electrically insulating layer.

30. 22. The resilient surface of claim 21, wherein the thickness of the thermally conductive sheet is greater than 6.3 micrometers. Wave filter assembly.

31. 22. The surface acoustic wave filter assembly of claim 21, wherein the thermally conductive layer comprises aluminum nitride.

32. 32. The surface acoustic wave filter assembly of claim 31, wherein the piezoelectric layer comprises lithium niobate.

33. The first surface acoustic wave filter has an interdigital transducer electrode covered with a silicon dioxide film.

22. The surface acoustic wave filter assembly of claim 21, further comprising a silicon.

34. 1. A radio frequency module, comprising: a power amplifier configured to provide a radio frequency signal; a surface acoustic wave filter configured to filter the radio frequency signal, a surface acoustic wave device including a piezoelectric layer; Other acoustic wave filters, A package enclosing the power amplifier, the surface acoustic wave filter, and the other surface acoustic wave filter Page and The heat from the surface acoustic wave filter is dissipated in a region corresponding to the other surface acoustic wave filter. a thermally conductive sheet configured to dissipate heat, the thermally conductive sheet being thinner than the piezoelectric layer; Includes a radio frequency module.

35. 3. A duplexer according to claim 2, wherein the duplexer includes the surface acoustic wave filter and the other surface acoustic wave filter. 4 radio frequency modules.

36. a radio frequency switch is provided in a signal path between the power amplifier and the surface acoustic wave filter; 35. The radio frequency module of claim 34, comprising:

37. 35. The method of claim 34, wherein the thermal conductivity of the thermally conductive layer is at least five times the thermal conductivity of the piezoelectric layer. Radio frequency module.

38. 1. A method for dissipating heat in a surface acoustic wave filter, comprising: By amplifying the radio frequency signal using a power amplifier, the amplified radio frequency signal and filtering the amplified radio frequency signal using a surface acoustic wave filter including a piezoelectric layer; Ringing and The heat associated with the filtering is transmitted using a thermally conductive sheet that is thinner than the piezoelectric layer. By dissipating the heat in one area corresponding to the other acoustic wave filter, To be done A method comprising:

39. 39. The method of claim 38, wherein the surface acoustic wave filter and the other filter are included on a single chip. method.

40. The surface acoustic wave filter is a transmission filter of a duplexer, and the other filter is 39. The method of claim 38, wherein the filter is a receive filter of a duplexer.

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