Compact high-power thin-film filter

Abstract

The thin film filter may include a monolithic substrate and a patterned conductive layer formed on the monolithic substrate. The patterned conductive layer may include at least one thin film inductor. The thin film filter may have a power capacity greater than about 25 W. In some embodiments, the thin film inductor may be connected between an input port and an output port. A heat sink terminal may be exposed along a bottom surface of the thin film filter. In some embodiments, the heat sink terminal may have an exposed heat sink area, and the bottom surface of the thin film filter has an area less than 20 times larger than the exposed heat sink area.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 126,014, filed on 16 December 2020, which is incorporated herein by reference in its entirety.

[0002] This subject generally concerns thin-film filters. More specifically, it concerns compact high-power thin-film filters. [Background technology]

[0003] The popularity of high-frequency wireless signal communication is increasing. The trend towards miniaturization is driving demand for small, passive components, which generally have lower power handling capacities. Miniaturization has also made surface mounting of small passive components difficult. Therefore, small, surface-mountable filters with high power handling capacities would be highly desirable in this field. [Overview of the project] [Means for solving the problem]

[0004] According to one embodiment of the present invention, the thin-film filter may include a monolithic substrate and a patterned conductive layer formed on the monolithic substrate. The patterned conductive layer may include at least one thin-film inductor. The thin-film filter may have a power capacity higher than about 25 W.

[0005] According to another embodiment of the present invention, the thin-film filter may include a monolithic substrate, an input port exposed on the bottom surface of the thin-film filter, and an output port exposed on the bottom surface of the thin-film filter. The thin-film filter may include a patterned conductive layer formed on the monolithic substrate. The patterned conductive layer may include at least one thin-film inductor connected between the input port and the output port. The thin-film filter may include a heat sink terminal exposed along the bottom surface of the thin-film filter. The heat sink terminal may have an exposed heat sink area. The footprint area of ​​the thin-film filter can be less than 20 times the size of the exposed heat sink area.

[0006] According to another embodiment of the present invention, a method for forming a thin film filter may include preparing a monolithic substrate and forming a patterned conductive layer on the monolithic substrate. The patterned conductive layer may include at least one thin film inductor connected between an input port exposed on the bottom surface of the thin film filter and an output port exposed on the bottom surface of the thin film filter. The method may include forming a heat sink terminal exposed along the bottom surface of the thin film filter.

[0007] A complete and feasible disclosure of the present invention, including the best mode of the invention, intended for those skilled in the art, is described herein with reference to the accompanying drawings. [Brief explanation of the drawing]

[0008] [Figure 1A] This is a simplified schematic diagram of a thin-film filter according to an embodiment of the present disclosure. [Figure 1B] This is a schematic diagram of a thin-film filter according to an aspect of the present disclosure. [Figure 1C] Figure 1B is a schematic side view of the thin-film filter. [Figure 2A] This is a schematic top view of another embodiment of a thin-film filter according to an aspect of the present disclosure. [Figure 2B] Figure 2A is a schematic side view of the thin-film filter. [Figure 3] This figure shows simulated insertion loss (S2,1) and return loss (S1,1) data for a low-pass thin-film filter according to an aspect of this disclosure. [Modes for carrying out the invention]

[0009] The repeated use of reference letters throughout this specification and the accompanying drawings is intended to represent identical or similar features or elements of the present invention.

[0010] A high-power thin-film filter with excellent power handling capabilities in a compact package is disclosed. The thin-film filter may include a monolithic substrate and at least one thin-film inductor formed on the monolithic substrate. The thin-film filter may have a power capacity higher than about 25W, higher than about 30W in some embodiments, higher than about 40W in some embodiments, higher than about 50W in some embodiments, higher than about 75W in some embodiments, higher than about 100W in some embodiments, and higher than about 150W in some embodiments.

[0011] Thin-film filters can be configured as compact, surface-mountable devices using, for example, grid array-type mounting (e.g., land grid array (LGA) type mounting, ball grid array (BGA) type, etc.). This combination may be desirable for ease of mounting and / or for applications where available mounting space on a printed circuit board is limited. For example, a thin-film filter may have a thickness of approximately 50 cm². 2 Less than, in some embodiments, about 45 cm 2 Less than, in some embodiments, about 40 cm 2 Less than, in some embodiments, about 35 cm 2 Less than, in some embodiments, about 20 cm 2 Less than, in some embodiments, about 15 cm 2 Less than, in some embodiments, about 10 cm2 Less than, in some embodiments about 7 cm 2 Less than, may have an installation area.

[0012] The filter may have a high power capacity with respect to the installation area of the filter in the X-Y plane. For example, the filter is about 0.02 W / mm 2 Higher than, in some embodiments about 0.1 W / mm 2 Higher than, in some embodiments about 0.15 W / mm 2 Higher than, in some embodiments about 0.2 W / mm 2 Higher than, in some embodiments about 0.22 W / mm 2 Higher than, may have an area power capacity.

[0013] The filter may have a high power capacity with respect to the volume of the filter. For example, the filter is about 0.02 W / mm 3 Higher than, in some embodiments about 0.1 W / mm 3 Higher than, in some embodiments about 0.15 W / mm 3 Higher than, in some embodiments about 0.2 W / mm 3 Higher than, in some embodiments about 0.22 W / mm 3 [[ID=3,1]]Higher than, may have a volume power capacity.

[0014] The filter can include various features that contribute to a high power capacitance. The filter can include a patterned conductive layer that forms one or more thin film inductors. The thin film inductor, as a thin film component, can be relatively thick. For example, in some embodiments, the thin film inductor can have a thickness in the range of from 20 micrometers to about 80 micrometers, in some embodiments from about 30 micrometers to about 70 micrometers, in some embodiments from about 40 micrometers to about 60 micrometers, and in some embodiments from about 45 micrometers to about 55 micrometers. Such thickness is known to reduce heat generation by the thin film inductor when a large power current is applied. In addition, such thickness is not so large as to prevent strong adhesion between the substrate and / or dielectric layer adjacent to the thin film inductor.

[0015] In contrast, the patterned conductive layer of other thin film components, such as the thin film capacitor and / or the resistive layer of the thin film resistor (if present), can have a thickness in the Z direction in the range of from about 0.05 micrometers to about 40 micrometers, in some embodiments from about 0.1 micrometers to about 20 micrometers, in some embodiments from about 0.3 micrometers to about 10 micrometers, and in some embodiments from about 1 micrometers to about 5 micrometers.

[0016] The thin film component can be accurately formed using various suitable subtractive, semi-additive, or full-additive processes. For example, physical vapor deposition and / or chemical deposition can be used. For example, in some embodiments, the thin film component can be formed using sputtering, which is a type of physical vapor deposition. However, other various suitable processes can also be used, including, for example, evaporation, atomic layer deposition (ALD), plasma-enhanced chemical vapor deposition (PECVD), electroless plating, and electroplating. Lithography masks and etching can be used to generate the desired shape of the thin film component. Various suitable etching techniques can be used, including dry etching using a plasma of a reactive or non-reactive gas (e.g., argon, nitrogen, oxygen, chlorine, boron trichloride, carbon tetrafluoride, sulfur hexafluoride), and / or wet etching.

[0017] The thin film inductor can include a patterned conductive layer that forms a loop. The loop can have a single loop diameter in the range of about 2 mm to about 9 mm, and in some embodiments, about 3 mm to about 7 mm. In some embodiments, the thin film inductor can include a loop-shaped, patterned conductive layer that is entirely formed on a single layer. For example, multiple thin film inductors can be completely formed in the same patterned conductive layer and / or in the plane. However, in other embodiments, the thin film inductor can include at least two patterned conductive layers that are spaced apart from each other in the thickness direction of the thin film filter and are connected by one or more vias. The patterned conductive layers can be spaced apart and disposed by one or more dielectric layers that include one or more suitable dielectric materials, including those described above with respect to the substrate.

[0018] The thin film inductor can have a line width, width in the X-Y plane, that is greater than about 0.1 mm, greater than about 0.2 mm in some embodiments, greater than about 0.3 mm in some embodiments, greater than about 0.5 mm in some embodiments, and greater than about 1 mm in some embodiments.

[0019] Another example of a feature that can improve the power capacity of a filter is that the filter may have heat sink terminals exposed along the bottom surface of the filter. The heat sink terminals may be configured to be attached (e.g., soldered) to a heat sink or other mounting surface of a printed circuit board. The heat sink terminals may have a relatively large exposed heat sink area relative to the filter. For example, the filter may have an installation area that is less than about 20 times larger than the exposed heat sink area, less than about 15 times larger in some embodiments, less than about 10 times larger in some embodiments, and less than 5 times larger in some embodiments. The exposed heat sink area may be about 5% or more, 7% or more in some embodiments, and about 10% or more in some embodiments, of the installation area of ​​the filter.

[0020] In addition, the exposed heat sink terminals can be made relatively long to allow for more uniform heat removal from the filter. This configuration can improve the thermal capacity of the filter by lowering the operating temperature of the filter with a given power. For example, the monolithic substrate may have a length in a first direction, the heat sink terminals may have a heat sink length in a first direction, and the ratio of the length of the monolithic substrate to the heat sink length is less than about 2, less than about 1.7 in some embodiments, less than about 1.5 in some embodiments, less than about 1.3 in some embodiments, and less than about 1.1 in some embodiments. In other words, in some embodiments, the length of the heat sink terminals may be about 50% or more of the length of the filter, about 70% or more in some embodiments, about 80% or more in some embodiments, and about 90% or more in some embodiments.

[0021] In some embodiments, the heat sink terminal can function as the ground for the thin film filter. The heat sink terminal can be connected to the ground of the device to which the thin film filter is connected (e.g., a printed circuit board). However, in other embodiments, a separate ground terminal can facilitate the ground connection to the device to which the thin film filter is connected. In such embodiments, one or more capacitors may be formed between the inductor and the ground terminal.

[0022] The input and output ports of the thin-film filter may be relatively large to help dissipate heat from the thin-film filter to the printed circuit board. For example, the input port may have an exposed input port area for connection to the printed circuit board. The output port may have an exposed output port area for connection to the printed circuit board. The bottom surface of the filter may have an area less than 150 times larger than the port exposure area, which can be defined as the sum of the exposed input port area and the exposed output port area, less than 120 times larger in some embodiments, less than 100 times larger in some embodiments, less than 80 times larger in some embodiments, less than 60 times larger in some embodiments, and less than 50 times larger in some embodiments.

[0023] In addition, in some embodiments, the total exposed area of ​​the input ports, output ports, and heatsink terminals can be made relatively large relative to the filter's installation area. The filter may have an installation area that is less than 20 times larger than the total exposed area of ​​the exposed input port area, exposed output port area, and exposed heatsink area, less than about 15 times larger in some embodiments, less than about 10 times larger in some embodiments, and less than 5 times larger in some embodiments.

[0024] Monolithic substrates can have relatively high thermal conductivity, which can improve the power handling capacity of devices. For example, monolithic substrates can have thermal conductivity higher than about 20 W / m·°C, higher than about 40 W / m·°C in some embodiments, higher than about 80 W / m·°C in some embodiments, and higher than about 100 W / m·°C in some embodiments.

[0025] The monolithic substrate and / or dielectric layer may include a material having a dielectric constant of less than about 30, less than about 25 in some embodiments, less than about 20 in some embodiments, and less than about 15 in some embodiments, as determined according to ASTM D2520-13 at an operating temperature of 25°C and a frequency of 500 MHz. However, in other embodiments, a material having a dielectric constant greater than 30 may be used to achieve higher frequencies and / or smaller components. For example, in such embodiments, the dielectric constant may range from about 30 to about 120 or higher, from about 50 to about 100 in some embodiments, and from about 70 to about 90 in some embodiments, as determined according to ASTM D2520-13 at an operating temperature of 25°C and a frequency of 500 MHz.

[0026] For example, the substrate and / or dielectric layer may comprise one or more suitable ceramic materials. Suitable materials are generally electrically insulating and thermally conductive. For example, in some embodiments, the substrate may include sapphire, ruby, alumina (Al2O3), aluminum nitride (AlN), beryllium oxide (BeO), aluminum oxide (Al2O3), boron nitride (BN), silicon (Si), silicon carbide (SiC), silica (SiO2), silicon nitride (Si3N4), gallium arsenide (GaAs), gallium nitride (GaN), zirconium dioxide (ZrO2), mixtures thereof, oxides and / or nitrides of such materials, or any other suitable ceramic material. Further exemplary ceramic materials include barium titanate (BaTiO3), calcium titanate (CaTiO3), zinc oxide (ZnO), ceramics including low-refractory glass, or other glass bonding materials.

[0027] As used herein, “formed on” may refer to a layer that is in direct contact with another layer. However, an intermediate layer may be formed between them. In addition, when used in reference to a base, “formed on” may be used in reference to the outer surface of a component. Thus, a layer “formed on” a base may be closer to the outside of the component than a layer formed on top of it.

[0028] Thin-film filters can be configured as various suitable filter types, including, for example, low-pass filters, high-pass filters, or band-pass filters. Filters may have characteristic frequencies (e.g., low-pass frequency, high-pass frequency, upper bound of band-pass frequency, or lower bound of band-pass frequency (e.g., stopband frequency)) in the range of about 100 MHz to about 5 GHz or higher, about 150 MHz to about 4 GHz in some embodiments, and about 200 MHz to about 3 GHz in some embodiments.

[0029] The filter may exhibit excellent filtering characteristics. For example, the filter may exhibit excellent out-of-band rejection. The filter may exhibit attenuation that decreases from the outer limit of the passband frequency range at a rate of at least 0.1 dB per MHz, at least 0.15 dB per MHz in some embodiments, and at least 0.2 dB per MHz in some embodiments.

[0030] As shown above, filters can generally be compact. For example, a filter may have a length of less than approximately 150 mm, less than approximately 100 mm in some embodiments, less than approximately 80 mm in some embodiments, less than approximately 50 mm in some embodiments, and less than approximately 40 mm in some embodiments. A filter may have a width of less than approximately 100 mm, less than approximately 60 mm in some embodiments, less than approximately 40 mm in some embodiments, less than approximately 30 mm in some embodiments, and less than approximately 20 mm in some embodiments.

[0031] The filter can be relatively thin. For example, the thickness of the filter can be greater than about 100 microns, greater than about 200 microns in some embodiments, greater than about 400 microns in some embodiments, greater than about 600 microns in some embodiments, greater than about 800 microns in some embodiments, greater than about 1 mm in some embodiments, and greater than about 2 mm in some embodiments.

[0032] The filter may have a number of conductive layers, non-conductive layer-forming structures (e.g., inductors, connectors, terminals, etc.), and connections between them, as described herein. In some embodiments, the filter may have multiple conductive layers, four or more conductive layers in some embodiments, and six or more conductive layers in some embodiments. I. Exemplary Embodiments Figure 1A shows a simplified schematic diagram of a filter 10 according to an aspect of the present disclosure. The filter may include one or more thin-film inductors 12, 14, 16 connected between an input port 18 and an output port 20. The thin-film inductors 12, 14, 16 may be connected in series. One or more capacitors 22, 24, 26, 28 may be connected between the thin-film inductors 12, 14, 16 and a heat sink terminal 30. In some embodiments, the heat sink terminal 30 may function as ground. In some embodiments, one or more capacitors 32, 34, 36 may be connected in series between the input port 18 and the output port 20. The capacitors 32, 34, 36 may each be connected in parallel with an individual inductor 12, 14, 16. For example, a first capacitor 32 may be connected in parallel with a first inductor 12. A second capacitor 34 may be connected in parallel with a second inductor 14. A third capacitor 36 may be connected in parallel with a third inductor 16.

[0033] It should be understood that the configuration described above with respect to Figure 1A is provided for illustrative purposes only. Modifications are possible within the scope of this disclosure. For example, the filter may include fewer or more inductors. In addition, some or all capacitors may be omitted to obtain the desired filtering characteristics.

[0034] Figure 1B shows a schematic diagram of a filter 100 according to an embodiment of the present disclosure. The filter 100 may have an installation area defined as the length 101 of the filter 100 multiplied by the width 103 of the filter. The filter 100 may include an input port 102 exposed on the surface 104 of a monolithic substrate 106. An output port 108 may also be exposed on the surface 104 of the monolithic substrate 106. A patterned conductive layer 109 can be formed on the monolithic substrate 106. The patterned conductive layer 109 may include one or more thin-film inductors 110, 112, 114. The thin-film inductors 110, 112, 114 can be connected between the input port 102 and the output port 108. In this example, the thin-film inductors 110, 112, 114 may include a first thin-film inductor 110, a second thin-film inductor 112, and a third thin-film inductor 114 connected in series between the input port 102 and the output port 108.

[0035] The filter 100 may include a heat sink terminal 116 exposed on the bottom surface of the monolithic substrate 106, as illustrated in Figure 1C, for example. The heat sink terminal 116 may be configured to be mounted or attached to a heat sink on the printed circuit board (or other object or surface) on which the filter 100 is mounted. The heat sink terminal 116 may have an exposed heat sink area. For example, the heat sink terminal 116 may have a rectangular shape including a length 118 and a width 120. In this example, the exposed heat sink area can be calculated by multiplying the length 118 by the width 119. However, it should be understood that the exposed heat sink terminal 116 can have a variety of shapes and sizes. For example, the heat sink terminal 116 may have an "L" shape, a "U" shape, or any other suitable shape.

[0036] The exposed heat sink area of ​​the heat sink terminal 116 can be made relatively large relative to the installation area of ​​the monolithic filter 106. The heat sink terminal 116 can have a large exposed area to help remove heat from the filter 116 (for example, to the heat sink of the printed circuit board), which facilitates high power capacity. In some embodiments, the monolithic substrate 116 can have an area less than 20 times larger than the exposed heat sink area of ​​the heat sink terminal 116.

[0037] In some embodiments, the filter 100 may include one or more capacitors. For example, an additional patterned conductive layer 120 may be positioned perpendicular to the surface 104 of the monolithic filter 106 and spaced apart from the patterned conductive layer 109 of the thin-film inductors 110, 112, and 114 in the thickness direction 115, as illustrated in Figure 1C. The additional patterned conductive layer 120 may form one or more capacitors together with the patterned conductive layer 109 of the thin-film inductors 110, 112, and 114.

[0038] For example, the patterned conductive layer 109 of the thin-film inductors 110, 112, and 114 may include one or more portions 122, 124, and 126 directly connected to the heat sink terminals 116. The additional patterned conductive layer 120 may include a first portion 128, a second portion 130, a third portion 132, and a fourth portion 134 that form capacitors between the thin-film inductors 110, 112 and the heat sink terminals 116. The first portion 128, the second portion 130, the third portion 132, and the fourth portion 134 of the additional patterned conductive layer 120 may correspond to the capacitors 22, 24, and 26 in Figure 1A, respectively, connected between the inductors 12, 14, and 16 and the heat sink terminals 30.

[0039] Firstly, the first portion 128 of the additional patterned conductive layer 120 can form a capacitor together with the patterned conductive layer 109 of the thin-film inductors 110 and 112. The first portion 128 of the additional patterned conductive layer 120 can overlap with the patterned conductive layer 109 with respect to the plane of the surface 104 of the monolithic substrate 106 having the patterned conductive layer 109 at a point between the first inductor 110 and the input port 102. The first portion 128 of the additional patterned conductive layer 120 can overlap with the first portion 122 of the patterned conductive layer 109. Thus, the first portion 128 of the additional patterned conductive layer 120 can form a capacitor between the patterned conductive layer 109 and the first portion 122 of the patterned conductive layer 109 at a point between the first inductor 110 and the input port 102. The first portion 128 of the additional patterned conductive layer 120 can correspond to capacitor 22 in Figure 1A.

[0040] Similarly, the second portion 130 of the additional patterned conductive layer 120 can overlap with the patterned conductive layer 109 at the point between the first inductor 110 and the second inductor 112. The second portion 130 of the additional patterned conductive layer 120 can overlap with the second portion 124 of the patterned conductive layer 109. Thus, the second portion 130 of the additional patterned conductive layer 120 can form a capacitor between the point between the first inductor 110 and the second inductor 112 and the second portion 124 of the patterned conductive layer 109. The second portion 130 of the additional patterned conductive layer 120 can correspond to the capacitor 24 in Figure 1A.

[0041] The third portion 132 of the additional patterned conductive layer 120 can overlap with the patterned conductive layer 109 at the point between the second inductor 112 and the third inductor 114. The second portion 130 of the additional patterned conductive layer 120 can overlap with the second portion 124 of the patterned conductive layer 109. Thus, the third portion 132 of the additional patterned conductive layer 120 can form a capacitor between the second portion 124 of the patterned conductive layer 109 and the point between the second inductor 112 and the third inductor 114. The third portion 130 of the additional patterned conductive layer 120 can correspond to the capacitor 26 in Figure 1A.

[0042] The fourth portion 134 of the additional patterned conductive layer 120 can overlap with the patterned conductive layer 109 at the point between the third inductor 114 and the output port 108. The fourth portion 130 of the additional patterned conductive layer 120 can overlap with the third portion 126 of the patterned conductive layer 109. Thus, the fourth portion 134 of the additional patterned conductive layer 120 can form a capacitor between the second portion 126 of the patterned conductive layer 109 and the point between the third inductor 114 and the output port 108. The fourth portion 130 of the additional patterned conductive layer 120 can correspond to capacitor 28 in Figure 1A. Thus, the first portion 128, the second portion 130, the third portion 132, and the fourth portion 134 of the additional patterned conductive layer 120 can correspond to capacitors 22, 24, and 26 in Figure 1A, respectively.

[0043] The additional patterned conductive layer 120 may include a fifth portion 136, a sixth portion 138, and a seventh portion 140, which can form capacitors corresponding to capacitors 32, 34, and 36 in Figure 1A, respectively. The capacitors can be connected in parallel with the respective inductors 110, 112, and 114. More specifically, the fifth portion 136 may overlap the patterned conductive layer 109 at a point between the first inductor 109 and the input port 102, and may also overlap the patterned conductive layer 109 at a point between the first inductor 110 and the second inductor 112. The sixth portion 138 may overlap the patterned conductive layer 109 at a point between the first inductor 109 and the second inductor 112, and may also overlap the patterned conductive layer 109 at a point between the second inductor 112 and the third inductor 114. Finally, the seventh portion 140 of the additional patterned conductive layer 120 can overlap with the patterned conductive layer 109 at a point between the second inductor 112 and the third inductor 114, and can also overlap with the patterned conductive layer 109 at a point between the third inductor 114 and the output port 108.

[0044] Figure 1C is a schematic side view of the filter 100 of Figure 1B. As shown in Figure 1C, a patterned conductive layer 109 can be placed on the surface 104 of the monolithic filter 106. A first layer 142 (e.g., made of a dielectric material) can be placed on top of the monolithic filter 106 and the patterned conductive layer 109. An additional patterned conductive layer 120 can be formed and / or placed on top of the first layer 142. In some embodiments, a second layer 144 can be placed on top of the additional patterned conductive layer 120 and the first layer 142. The input port 102, output port 108, and heat sink terminal 116 can be exposed along the bottom surface 146 of the filter 100. If the filter is surface-mounted (e.g., on a printed circuit board) such that the ports 102 and 108 are in contact with the mounting surface, as discussed above, the filter 100 can be configured as a "flip-chip" so that the filter 100 can be flipped 180 degrees from the orientation shown in Figure 1C.

[0045] Figure 2A is a schematic top view of another embodiment of the filter 200 according to an aspect of the present disclosure. The filter 100 may have an installation area defined as the length 101 of the filter 100 multiplied by the width 103 of the filter. The filter 200 may generally be configured similarly to the filter 100 in Figure 1. The reference numerals in Figures 2A and 2B correspond approximately to the reference numerals in Figure 1. For example, the input port 202 of the filter 200 in Figure 2A corresponds to the input port 102 of the filter 100 in Figure 1, and the surface 204 of the monolithic substrate 206 of the filter 200 in Figure 2A corresponds to the monolithic substrate 106 of the filter 100 in Figure 1.

[0046] In contrast to filter 100 in Figure 1, filter 200 in Figure 2 can omit the capacitors corresponding to capacitors 32, 34, and 36 in Figure 1A. In other words, filter 200 in Figure 2A can omit the capacitors connected in parallel with each inductor 210, 212, and 214. However, it should be understood that in some embodiments, such capacitors can be included in filter 200 in Figure 2 within the scope of this disclosure.

[0047] In addition, the inductors 210, 212, and 214 of the filter 200 in Figure 2A can be formed on multiple patterned conductive layers and connected by vias 246, 248, 250, 252, 254, and 256. For example, the third patterned conductive layer 258 may include a first portion 260, a second portion 262, and a third portion 264, each forming part of the loops of the inductors 210, 212, and 214. The portions 260, 262, and 264 of the third layer 258 can be connected to a conductive layer 209 patterned by vias 246, 248, 250, 252, 254, and 256 as shown in Figure 2A (for example, corresponding to the patterned conductive layer 109 of the filter 100 in Figures 1B and 1C).

[0048] Figure 2B is a schematic side view of the filter 200 of Figure 2A. As shown in Figure 2B, the filter may include a third layer 258 which can be placed on the monolithic substrate 206 (for example, between the first patterned conductive layer 209 and the monolithic substrate 206). (The first patterned conductive layer 209 may correspond to the patterned conductive layer 109 of the filter 100 in Figures 1B and 1C). The third layer 259 (for example, made of a dielectric material) can be placed on the monolithic substrate 206 and the third patterned conductive layer 258. However, it should be understood that the filter configuration described with respect to Figure 2A can be achieved using any suitable arrangement of the dielectric layer and the patterned conductive layer. II. Simulation Data Figure 3 shows the simulated insertion loss (S) of a low-pass filter according to an aspect of this disclosure. 2,1 ) and return loss (S 1,1 The data for the simulation shows excellent attenuation at frequencies higher than the 512MHz low-pass cutoff frequency. More specifically, Figure 5 shows a sharp drop after passing the low-pass cutoff frequency. In this example, the insertion loss (S 2,1 The attenuation is -0.306 dB at 512 MHz and -41.47 dB at 687.0 MHz. At frequencies higher than approximately 700 MHz, the attenuation is less than -30 dB. III. Test A. Response characteristics Testing of insertion loss, return loss, and other response characteristics can be performed using a source signal generator (e.g., the 1306 Keithley 2400 series source measure unit (SMU), e.g., the Keithley 2410-C SMU). For example, to measure S-parameters (e.g., insertion loss, return loss, etc.), a source signal generator can be used to measure the input signal at the filter's input port and the power signal at the filter's output port. B. Response Characteristics Power capacity testing can be performed using a source signal generator (e.g., a 1306 Keithley 2400 series source measure unit (SMU), e.g., a Keithley 2410-C SMU) and an infrared thermometer. The power capacity of a filter can be defined as the power level at which the filter has a steady-state temperature of approximately 75°C in an ambient environment of approximately 23°C. To measure power capacity, a test signal with a 500 MHz sinusoidal frequency and a 0V DC bias voltage can be applied to the filter using a source signal generator (e.g., a 1306 Keithley 2400 series source measure unit (SMU), e.g., a Keithley 2410-C SMU). The power level of the test signal can be increased stepwise (e.g., by 10 watts) in an environment of approximately 23°C. The filter assembly can reach its steady-state temperature at each steady-state power level. Each steady-state temperature of the filter can be measured using an infrared thermometer. This process can be repeated until the filter temperature exceeds 75°C. The power level just before the filter temperature exceeds 75°C can be determined as the filter's power capacity.

[0049] These and other modifications and variations of the present invention can be carried out by those skilled in the art without departing from the spirit and scope of the invention. In addition, it should be understood that the aspects of the various embodiments may be interchangeable in whole or in part. Furthermore, those skilled in the art will understand that the foregoing description is merely an example and is not intended to limit the invention to what is further described in the appended claims.

Claims

1. It is a thin-film filter, Monolithic substrate and A patterned conductive layer formed on the monolithic substrate, comprising at least one thin-film inductor, An input port exposed on the bottom surface of the thin film filter, having an exposed input port area, An output port exposed on the bottom surface of the thin film filter, having an exposed output port area, A heat sink terminal exposed on the bottom surface of the thin film filter, having an exposed heat sink region, Equipped with, The at least one thin-film inductor is positioned between the surface of the monolithic substrate and the bottom surface of the thin-film filter. The thin-film filter has a power capacity higher than 25W.

2. The aforementioned thin film filter is 50 cm ２ The thin-film filter according to claim 1, having an installation area that is less than [amount missing].

3. The thin film filter has a density of 0.02 W / mm². ２ The thin-film filter according to claim 1, which has a higher regional power capacity than the above.

4. The thin-film filter according to claim 1, wherein the thin-film inductor has a thickness greater than 30 micrometers.

5. The thin film filter according to claim 1, wherein the installation area of ​​the thin film filter is less than 20 times the size of the exposed heat sink area.

6. The thin film filter according to claim 1, wherein the installation area of ​​the thin film filter is less than 20 times the total exposed area of ​​the exposed input port area, the exposed output port area, and the exposed heat sink area.

7. The thin-film filter according to claim 1, wherein the at least one thin-film inductor is connected between the input port and the output port.

8. The thin-film filter according to claim 7, wherein the at least one thin-film inductor comprises a plurality of thin-film inductors connected in series between the input port and the output port.

9. The heat sink terminals exposed along the bottom surface of the filter, The thin film filter further comprises an additional patterned conductive layer spaced apart from the patterned conductive layer in the thickness direction, The thin-film filter according to claim 7, wherein the additional patterned conductive layer, together with the patterned conductive layer and the heat sink terminals, forms a capacitor.

10. The thin-film filter according to claim 1, wherein the monolithic substrate comprises sapphire.

11. The thin-film filter according to claim 1, wherein the monolithic substrate has a thermal conductivity higher than 20 W / m·°C.

12. The thin-film filter according to claim 1, wherein the at least one thin-film inductor comprises a loop-shaped patterned conductive layer formed entirely on a single layer.

13. The thin film filter according to claim 1, wherein the at least one thin film inductor comprises at least two patterned conductive layers spaced apart from each other in the thickness direction of the thin film filter.

14. The thin film filter according to claim 1, wherein the thin film filter exhibits attenuation of less than -30 dB at frequencies higher than the stopband frequency.

15. It is a thin-film filter, Monolithic substrate and An input port exposed on the bottom surface of the thin film filter, having an exposed input port area, An output port exposed on the bottom surface of the thin film filter, having an exposed output port area, A patterned conductive layer formed on the monolithic substrate, the patterned conductive layer comprising at least one thin-film inductor, the at least one thin-film inductor connected between the input port and the output port, and the patterned conductive layer disposed between the surface of the monolithic substrate and the bottom surface of the thin-film filter, A heat sink terminal exposed along the bottom surface of the thin film filter, having an exposed heat sink region, Equipped with, The heat sink terminal has an exposed heat sink area, and the installation area for the thin film filter is less than 20 times the size of the exposed heat sink area. , thin film filter.

16. The aforementioned thin film filter is 50 cm ２ The thin film filter according to claim 15, having an installation area that is less than [amount missing].

17. The thin film filter has a density of 0.02 W / mm². ２ The thin-film filter according to claim 15, which has a higher regional power capacity than the above.

18. The thin-film filter according to claim 15, wherein the thin-film inductor has a thickness greater than 30 micrometers.

19. The thin film filter according to claim 15, wherein the installation area of ​​the thin film filter is less than 20 times the size of the total exposed area of ​​the exposed input port area, the exposed output port area, and the exposed heat sink area.

20. The heat sink terminal has a heat sink length in the first direction, The thin-film filter according to claim 15, wherein the monolithic substrate has a length in the first direction that is less than twice the length of the heat sink.

21. The thin-film filter according to claim 20, wherein the at least one thin-film inductor comprises a plurality of thin-film inductors connected in series between the input port and the output port.

22. The thin film filter according to claim 20, further comprising an additional patterned conductive layer spaced apart from the patterned conductive layer in the thickness direction of the thin film filter, wherein the additional patterned conductive layer together with the patterned conductive layer and the heat sink terminals form a capacitor.

23. The thin-film filter according to claim 15, wherein the monolithic substrate comprises sapphire.

24. The thin-film filter according to claim 15, wherein the monolithic substrate has a thermal conductivity higher than 20 W / m·°C.

25. The thin-film filter according to claim 15, wherein the at least one thin-film inductor comprises a loop-shaped patterned conductive layer formed entirely on a single layer.

26. The thin film filter according to claim 15, wherein the at least one thin film inductor comprises at least two patterned conductive layers spaced apart from each other in the thickness direction of the thin film filter.

27. The thin film filter according to claim 15, wherein the thin film filter exhibits attenuation of less than -30 dB at frequencies higher than the stopband frequency.

28. A method for forming a thin film filter, Steps to prepare a monolithic substrate, A step of forming a patterned conductive layer formed on the monolithic substrate, wherein the patterned conductive layer comprises at least one thin-film inductor, the at least one thin-film inductor is connected between an input port exposed on the bottom surface of the thin-film filter and an output port exposed on the bottom surface of the thin-film filter, and is positioned between the surface of the monolithic substrate and the bottom surface of the thin-film filter, The steps include forming a heat sink terminal exposed along the bottom surface of the thin film filter, and Methods that include...

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