Radio frequency package and manufacturing method thereof

Abstract

The invention relates to a radio frequency package and a method of manufacturing the same. A radio frequency (RF) package includes: an RF chip; a coupling element configured to couple an RF signal into or out of the RF package; an RF signal path coupling the RF chip and the coupling element; and a waveguide disposed in the RF signal path, in which the waveguide is disposed inside the RF package and includes a first metal layer, a second metal layer opposite the first metal layer, and a first groove formed in the first metal layer, in which a main portion of the first groove is disposed perpendicular to a propagation direction of the waveguide.

Description

Technical Field

[0001] This disclosure relates to radio frequency (RF) packaging and methods for manufacturing RF packages. Background Technology

[0002] For radio frequency (RF) transmitter or transceiver packages (such as radar systems), out-of-band radiation can violate EMI / EMC (electromagnetic interference / electromagnetic compatibility) requirements. For example, a significant component of out-of-band radiation may occur at the second harmonic of the fundamental frequency band. Conventional RF packages can implement complex and expensive preventative measures to suppress unwanted out-of-band output.

[0003] Manufacturers and developers of RF packages are constantly striving to improve their products. In this context, it may be desirable to provide RF packages with low out-of-band output that meet EMI / EMC requirements. Additionally, it may be desirable to provide simple and cost-effective methods for manufacturing such RF devices. Summary of the Invention

[0004] One aspect of this disclosure relates to a radio frequency (RF) package. The RF package includes: an RF chip; a coupling element configured to couple RF signals into or out of the RF package; an RF signal path coupling the RF chip and the coupling element; and a waveguide disposed in the RF signal path. The waveguide is disposed within the RF package and includes a first metal layer, a second metal layer opposite to the first metal layer, and a first trench formed in the first metal layer, wherein a major portion of the first trench is arranged perpendicular to the propagation direction of the waveguide.

[0005] Another aspect of this disclosure relates to a method for manufacturing an RF package. The method includes the action of generating an RF chip. The method also includes the action of generating a coupling element configured to couple RF signals into or out of the RF package. The method further includes the action of coupling the RF chip and the coupling element via an RF signal path. The method also includes the action of generating a waveguide in the RF signal path, wherein the waveguide is disposed within the RF package and includes a first metal layer and a second metal layer opposite to the first metal layer. The method further includes the action of forming a first trench in the first metal layer, wherein a major portion of the first trench is arranged perpendicular to the propagation direction of the waveguide.

[0006] Those skilled in the art will recognize the additional features and advantages upon reading the following detailed description and reviewing the accompanying drawings. Attached Figure Description

[0007] The present disclosure is illustrated in the accompanying drawings by way of example and not limitation, and in the pictures of the drawings, the same reference numerals refer to similar or identical elements. The elements in the drawings are not necessarily proportional to each other. Features of the various illustrated examples can be combined unless excluded from each other.

[0008] Figure 1 A cross-sectional side view of the RF package 100 according to the present disclosure is schematically illustrated.

[0009] Figure 2 includes Figure 2A and 2B The diagram shows a cross-sectional side view and a perspective view of a substrate integrated waveguide (SIW) 200 that may be included in an RF package according to the present disclosure.

[0010] Figure 3 includes Figures 3A to 3C The diagram shows a cross-sectional side view, top view, and perspective view of the SIW 300 that may be included in an RF package according to this disclosure.

[0011] Figure 4 The illustration shows a top view of the SIW 400 that may be included in an RF package according to this disclosure.

[0012] Figure 5 The illustration shows a top view of the SIW 500 that may be included in an RF package according to this disclosure.

[0013] Figure 6 The illustration shows a top view of the SIW 600 that may be included in an RF package according to this disclosure.

[0014] Figure 7 includes Figure 7A and Figure 7B It shows the electric field distribution of the waveguide in TE10 and TE20 modes.

[0015] Figure 8 includes Figures 8A to 8C It illustrates various insertion losses of conventional waveguides and waveguides according to this disclosure.

[0016] Figure 9 A flowchart illustrating a method for manufacturing an RF device according to the present disclosure is shown. Detailed Implementation

[0017] In the following detailed description, reference is made to the accompanying drawings, in which specific aspects of this disclosure may be practiced illustratively. In this regard, directional terms such as “top,” “bottom,” “front,” “back,” etc., may be used with reference to the orientation of the described drawings. Since components of the described device can be positioned in several different orientations, directional terms are for illustrative purposes and not for limitation. Other aspects may be utilized, and structural or logical changes may be made without departing from the concept of this disclosure. Therefore, the following detailed description should not be considered limiting, and the concept of this disclosure is defined by the appended claims.

[0018] Now for reference Figure 1 An exemplary radio frequency (RF) package 100 according to the present disclosure is shown. For example, the RF package 100 may be an FCBGA (Flip Chip Ball Grid Array) package. However, it should be understood that the present disclosure is not limited to this package type, but can also be practiced in RF packages of different types and designs. The RF package 100 may include an RF chip 2 and a coupling element 4, which may be coupled via an RF signal path 6 indicated by a dashed line. The coupling element 4 may be configured to couple RF signals into or out of the RF package 100, as indicated by the bidirectional arrows. The RF package 100 may also include a waveguide 8 disposed in the RF signal path 6, wherein the waveguide 8 may be disposed within the RF package 100. Detailed designs and structures of exemplary waveguides that may be used in RF packages according to the present disclosure are shown and described below. In the illustrated example, the RF package 100 may include a substrate 10, wherein the RF chip 2 may be disposed on a first main surface 12A of the substrate 10, and the coupling element 4 may be disposed on a second main surface 12B of the substrate 10 opposite to the first main surface 12A. The waveguide 8 may be disposed within the substrate 10.

[0019] The substrate 10 may include a dielectric material and multiple metal layers, which are not shown for simplicity. The metal layers may be disposed on a first main surface 12A, a second main surface 12B, and / or within the dielectric material, and may particularly extend in the xy plane. Metal layers disposed at different levels relative to the z-direction may be electrically connected via conductive vias extending through the dielectric material. Specifically, waveguides 8 disposed in the substrate 10 may be formed of metal layers and dielectric material. The RF chip 2 may be electrically and mechanically coupled to the first main surface 12A of the substrate 10 via multiple electrical connection elements 14. Specifically, the electrical connection elements 14 may provide electrical connections between electrical contacts of the RF chip 2 and one or more metal layers disposed on the first main surface 12A of the substrate 10.

[0020] RF chip 2 can be made of any semiconductor material or can include any semiconductor material (such as, for example, silicon). RF chip 2 (or its electronic circuitry) can be configured to operate in a frequency range greater than about 1 GHz, and in some examples greater than about 10 GHz. RF chip 2 can therefore also be referred to as a radio frequency chip, a high-frequency chip, or a microwave frequency chip. More specifically, RF chip 2 can be configured to operate in an RF range or microwave frequency range that can range from about 1 GHz to about 1 THz, and more specifically from about 10 GHz to about 300 GHz. Microwave circuitry can include, for example, a microwave transmitter, a microwave receiver, a microwave transceiver, a microwave sensor, a microwave detector, etc. The RF device according to this disclosure can be used in radar applications in which the frequency of the RF signal can be modulated. Therefore, RF chip 2 can also be referred to as a radar chip. In particular, RF chip 2 can include or can correspond to an MMIC (monolithic microwave integrated circuit).

[0021] Radar microwave equipment can be used, for example, in automotive, industrial, military, and / or defense applications for distance and speed measurement systems. Automotive applications, for instance, may include advanced driver assistance systems, automatic vehicle cruise control systems, vehicle collision avoidance systems, etc. Such systems can operate in the microwave frequency range and can utilize FMCW (Frequency Modulated Continuous Wave) signals, such as in the 24 GHz, 76 GHz, or 79 GHz bands. The use of radar microwave systems can provide vehicles with constant and efficient driving. Efficient driving can, for example, reduce fuel consumption, leading to reduced CO2 emissions and energy savings. Furthermore, it can reduce wear on vehicle tires, brake discs, and brake pads, thereby reducing fine dust pollution. As specified herein, improved RF or radar systems can therefore contribute to green technology solutions (i.e., climate-friendly solutions that provide reduced energy use).

[0022] The coupling element 4 can be configured to couple RF signals into or out of the substrate 10. Accordingly, the coupling element 4 can be referred to as a transmit / receive element and / or the RF package 100 can be referred to as an RF transceiver package. In the illustrated example, a single coupling element 4 is shown for simplicity. However, in other examples, the RF package 100 may include additional coupling elements, the number of which may depend on or correspond to the number of RF channels of the RF chip 2. Specifically, each coupling element 4 may be associated with a corresponding RF channel of the RF chip 2. In some examples, the coupling element 4 may include or correspond to one or more antennas, which may, for example, be formed in one or more metal layers of the substrate 10. In the illustrated example, the coupling element 4 may be arranged at the second main surface 12B of the substrate 10.

[0023] RF package 100 may be mounted on a printed circuit board (PCB) 16, which may or may not be considered part of RF package 100. Mechanical and electrical connections between substrate 10 and PCB 16 may be established using multiple electrical connection elements 18, such as solder balls or solder libraries. PCB 16 may include at least one opening 20 aligned with coupling element 4 and extending through PCB 16 in the z-direction. In some examples, RF package 100 may include at least one waveguide antenna (not shown), wherein coupling element 4 may be configured to couple RF signals to the corresponding waveguide antenna via the aligned opening 20 and / or vice versa. In this context, RF package 100 may include an AFIP (Antenna-in-Package Feed), wherein coupling element 4 may correspond to a transmitter or transmitter structure. The transmitter may be coupled to a corresponding RF port of RF chip 2 to transmit RF signals between the RF port and the waveguide antenna.

[0024] RF package 100 may optionally include a sealing material 22 that can at least partially seal the components of RF package 100. In the illustrated example, sealing material 22 may be disposed on a first main surface 12A of substrate 10 and may at least partially cover RF chip 2. Sealing material 22 may include or may be made of at least one of epoxy resin, filled epoxy resin, glass fiber filled epoxy resin, imide, thermoplastic, thermosetting polymer, polymer blend, molding compound, etc. Various techniques may be used to seal the components of RF package 100 in sealing material 22, such as compression molding, injection molding, powder molding, liquid molding, mapping molding, etc.

[0025] Now for reference Figure 2A and 2B Figure 2 shows a cross-sectional side view and perspective view of the substrate integrated waveguide (SIW) 200. Figure 2 only shows a portion of the SIW 200 that can be further extended in the x-direction. For example, the SIW 200 can be arranged on... Figure 1 In the RF package 100. In some transceiver packages, SIW can be used as the primary RF transmission structure because they are robust to manufacturing tolerances. SIW 200 may include a first metal layer 24A, a second metal layer 24B opposite to the first metal layer 24A, and a dielectric material 26 disposed between the first metal layer 24A and the second metal layer 24B. Return to Reference Figure 1For example, the metal layers 24A, 24B and dielectric material 26 of SIW 200 may be part of or disposed within the substrate 10. The first metal layer 24A may be referred to as the top metal layer of SIW 200, and the second metal layer 24B may be referred to as the bottom metal layer of SIW 200. SIW 200 may include a first plurality of first via connections 28A that may extend between the first metal layer 24A and the second metal layer 24B. The first via connections 28A may be arranged to form a via fence.

[0026] SIW 200 may consist of a dielectric material 26 covered on two surfaces by a first metal layer 24A and a second metal layer 24B. The dielectric material 26 may embed first via connections 28A, which may form two rows of parallel metal vias defining the propagation area of ​​electromagnetic waves to be transmitted via SIW 200. The propagating electromagnetic waves may be constrained within the dielectric material 26 by the metal layers 24A and 24B on each of the two surfaces of the dielectric material 26 and between the two rows of first metal vias 28A connecting the metal layers 24A and 24B. In the illustrated example, SIW 200 may be configured to transmit electromagnetic waves in the x-direction. In other words, the propagation direction of SIW 200 may extend in the x-direction. SIW 200 may also include a third metal layer 24C disposed above the first metal layer 24A and a fourth metal layer 24D disposed below the second metal layer 24B. It should be noted that, for illustrative purposes, in Figure 2B Metal layers 24C and 24D are not shown in the perspective view. In the illustrated example, dielectric material 26 may also be disposed between the first metal layer 24A and the third metal layer 24C, and between the second metal layer 24B and the fourth metal layer 24D.

[0027] Now for reference Figures 3A to 3C Figure 3 shows a cross-sectional side view, top view, and perspective view of SIW 300. SIW 300 of Figure 3 may include some or all of the features of SIW 200 of Figure 2. Figure 3 only shows a portion of SIW 300 that may further extend in the x-direction. For example, SIW 200 and SIW 300 of Figures 2 and 3 can be considered as two parts of the same SIW. SIW 300 can be arranged in an RF package according to this disclosure (e.g., Figure 1The SIW 300 may include a first trench 30A formed in a first metal layer 24A, wherein the main portion of the first trench 30A may be arranged perpendicular to the propagation direction of the SIW 300. In the illustrated example, the propagation direction of the SIW 300 may extend in the x-direction, while the first trench 30A may extend in the y-direction. The exemplary propagation of the RF signal through the SIW 300 is indicated by an arrow pointing in the x-direction. Typically, the position of the first trench 30A relative to the x-direction can be arbitrarily chosen and can depend in particular on the design and structure of the RF package 100. In particular, the first trench 30A may be arranged along the SIW 300, i.e., not necessarily at the input or output location of the SIW 300, but anywhere therein.

[0028] In the non-limiting example of Figure 3, the first groove 30A can have a straight or linear shape. The total length l of the first groove 30A is... total It can be approximately equal to λ / 2, where λ is the wavelength (or effective wavelength) at the location of the first slot 30A associated with the second harmonic of the operating frequency of RF chip 2. The total length l of the first slot 30A total It can be adapted to signal frequencies and / or used for tuning frequencies. The (effective) wavelength λ of the electromagnetic radiation transmitted in the SIW 300 can depend on various properties. For example, the wavelength λ can depend on the size and shape of the SIW 300. The wavelength of electromagnetic radiation in the waveguide can be directly related to the physical dimensions of the waveguide (such as its width, height, and length). The dimensions of the waveguide can determine the propagation modes present within it, which in turn affect the wavelength of the radiation. Furthermore, the wavelength λ can depend on the material of the SIW 300. The wavelength of electromagnetic radiation in the waveguide can depend on the material properties of the waveguide (such as its dielectric constant and conductivity). These material properties may affect the speed at which electromagnetic waves propagate through the waveguide, which in turn affects the wavelength of the radiation. In addition, the wavelength λ can depend on the frequency of the electromagnetic radiation, i.e., the operating frequency of the RF chip 2. The wavelength of electromagnetic radiation in the waveguide can be inversely proportional to the frequency of the radiation (i.e., λ = c / f), where c is the speed of light and f is the frequency of the radiation. It should be understood that in practice, the length of the first slot 30A does not need to precisely match the value of λ / 2, but can be optimized or tuned relative to one or more of the properties mentioned above. For example, the length of the first slot 30A can deviate from the value of λ / 2 by less than approximately 20%, 15%, 10%, 5%, 4%, 3%, 2%, or 1%.

[0029] The first slot 30A can be aligned with the lobe of the electric field distribution of the SIW 300's TE10 mode. In the context, Figure 7A The diagram illustrates the electric field distribution of the TE10 mode in a waveguide (such as SIW 300), particularly when viewed in the x-direction. From Figure 7AAs can be seen from the example, the lobes or maximum values ​​of the electric field distribution in the TE10 mode can be located at the center of the SIW 300 relative to the y-direction. Therefore, from Figure 3B As can be seen from the top view, the first slot 30A can be positioned at the center of the first metal layer 24A or arranged in the middle of the first metal layer 24A relative to the y direction.

[0030] Due to its length and position, the first slot 30A can be configured to suppress the second harmonic of the RF signal transmitted in the SIW 300 at the operating frequency of the RF chip 2. More specifically, the first slot 30A can be configured to suppress the second harmonic of the TE10 mode. In other words, the first slot 30A can be configured to suppress the transmission of the TE10 mode at the second harmonic frequency in the SIW 300. In this regard, performance at the fundamental frequency band may not necessarily be affected. It should be noted that forming a single slot in the first metal layer 24A can be considered as the most basic structure for suppressing the second harmonic of the TE10 mode. The first slot 30A can be configured as a resonator (or slot resonator) in the first metal layer 24A (i.e., the top surface) of the SIW 300. More specifically, the first slot 30A can be configured to generate a short circuit and / or a second harmonic reflected back to the RF signal at the second harmonic of the RF signal. As will be discussed later... Figures 8A to 8C The first slot 30A discussed herein may be specifically configured to suppress the second harmonic of the RF signal transmitted in the waveguide according to the present disclosure at the operating frequency of the RF chip 2 better than about 10 dB within a 10% fractional bandwidth.

[0031] SIW 300 may include a second plurality of second via connections 28B extending between a first metal layer 24A and a third metal layer 24C, wherein, when viewed in a direction perpendicular to the first metal layer 24A (i.e., when viewed in the z-direction), the second via connections 28B may at least partially surround the first slot 30A. The second via connections 28B and the third metal layer 24C may form an electrical shielding structure or electrical shielding cage that at least partially surrounds the first slot 30A. The electrical shielding structure may be configured to shield and / or prevent radiation exiting SIW 300 through the first slot 30A from penetrating into other areas of the RF package. A portion of the third metal layer 24C forming the top surface of the electrical shielding structure may be (particularly) completely closed, i.e., without any openings. Therefore, practically, in Figure 3B Top view and Figure 3C In the perspective view, the second via connection 28B can be covered by the third metal layer 24C and is therefore not visible. For in Figure 3B The same applies to the first via connection 28A, indicated by the small dashed circle in the top view.

[0032] exist Figure 3BIn the exemplary top view, the second via connection 28B can be arranged in a rectangular shape. In this context, the second via connection 28B (or more specifically, the rectangle formed by the second via connections 28B) can include: a first row of second via connections 28B, arranged to the left of the first slot 30A and extending in the y-direction; a second row of second via connections 28B, arranged to the right of the first slot 30A and extending in the y-direction; a third row of second via connections 28B, arranged above the first slot 30A and extending in the x-direction; and a fourth row of second via connections 28B, arranged below the first slot 30A and extending in the x-direction. In the illustrated example, when viewed in the z-direction, the entire second via connection 28B can completely surround the first slot 30A. That is, in Figure 3B In the top view, the first slot 30A may be entirely located within the area or region defined by the second via connection 28B. In the illustrated example, the first slot 30A may not necessarily be centered relative to the x-direction within the rectangular shape of the second via connection 28B, but may be slightly shifted to the right for tuning purposes.

[0033] In another example, when viewed in the z-direction, the second via connection 28B may include a first row and a second row of second via connections 28B arranged on the left and right sides of the first slot 30A, but may not necessarily include a third row and a fourth row of second via connections 28B arranged above and below the first slot 30A. Specifically, when viewed in the z-direction, the second via connection 28B may extend at least along both sides of the main portion of the first slot 30A. Figure 3B In the exemplary top view, this means that the second via connection 28B can extend along the total length l of the first slot 30A. total It extends at least to the left and right sides of the first slot 30A.

[0034] Now for reference Figure 4 The diagram shows a top view of the SIW 400, which can be included in an RF package (e.g., according to this disclosure) Figure 1 In the RF package 100). Figure 4 The SIW 400 can include some or all of the features of the waveguide previously described. In the illustrated example, the first slot 30A can be U-shaped. That is, in Figure 4 In the exemplary top view, the shape of the first groove 30A can resemble the shape of the letter "U". In other examples, the first groove 30A can be formed differently (such as being V-shaped or C-shaped). The U-shape of the first groove 30A can include one or more sharp corners and / or one or more rounded corners. In the illustrated example, the U-shape can have multiple sharp corners.

[0035] The U-shaped first groove 30A may include: a first portion 32 having a first length l1 and extending in the y-direction; a second portion 34A having a second length l2 and extending in the x-direction; and a third portion 34B having a third length l3 and extending in the x-direction. Each of the second portion 34A and the third portion 34B may be arranged substantially perpendicular to the first portion 32, and the second portion 34A and the third portion 34B may be substantially parallel to each other. In the illustrated case, I2 may be substantially equal to I3. In particular, the first length l1 may be greater than each of the second length l2 and the third length l3 (i.e., l1>l2 and l1>l3). Furthermore, the first length l1 may be greater than the sum of the second length l2 and the third length l3 (i.e., l1>l2+l3). Thus, the first portion 32 may correspond to the main portion of the first groove 30A, which may be arranged perpendicular to the propagation direction of SIW 400. In the illustrated example, the U-shape of the first groove 30A may open to the left. Alternatively, in another example, the U-shape of the first slot 30A can open to the right.

[0036] Similar to the example in Figure 3, the total length l of the first slot 30A total It can be essentially equal to λ / 2, where λ is the effective wavelength at the location of the first slot 30A associated with the second harmonic of the operating frequency of RF chip 2. That is, in the illustrated example, l total = l1 + l2 + l3 ≈ λ / 2. Similarly, the first slot 30A can be aligned with the lobe of the electric field distribution of the TE10 mode of the SIW 400, such that the first slot 30A can be configured to suppress the second harmonic of the RF signal transmitted in the SIW 400 at the operating frequency of the RF chip 2. In particular, if the dimension of the SIW 400 in the y-direction is too small or too short for a straight first slot 30A, a U-shaped (or V-shaped or C-shaped) first slot 30A can be used. In other words, the U-shaped (or V-shaped or C-shaped) first slot 30A can be more compact than the straight one, and therefore has a similar total length l to the first slot 30A. total However, compared to the arrangement in Figure 3, which is shaped into a straight line, it can provide a smaller shape factor.

[0037] Now for reference Figure 5 The diagram shows a top view of the SIW 500, which can be included in an RF package (such as...) according to this disclosure. Figure 1 In the RF package 100). Figure 5 The SIW 500 can include some or all of the characteristics of the waveguides previously described. Similar to... Figure 4For example, the SIW 500 may include a first trench 30A formed in the first metal layer 24A. Furthermore, the SIW 500 may include a second trench 30B formed in the first metal layer 24A, wherein the second trench 30B may be arranged adjacent to the first trench 30A relative to the propagation direction of the SIW 500 (i.e., relative to the x-direction). Similar to the first trench 30A, the second trench 30B may be aligned with the lobes of the electric field distribution of the TE10 mode of the SIW 500, and / or the length of the second trench 30B may be substantially equal to λ / 2, where λ is the effective wavelength at the location of the second trench 30B associated with the second harmonic of the operating frequency of the RF chip 2. Forming multiple trenches in the first metal layer 24A can enhance performance and / or increase bandwidth. Using only a single trench may only provide a notch in the frequency response, making its bandwidth potentially too limited for some applications. In contrast, multiple trenches that can be slightly tuned to different but very close frequencies can be cascaded to increase bandwidth. In the illustrated example, a structure including an exemplary number of two trenches is shown. However, in further examples, the number of slots can be increased. In the case shown, slots 30A and 30B can have similar shapes (such as U-shapes). In other examples, slots 30A and 30B can have different shapes, where each slot 30A and slot 30B can be one of U-shape, V-shape, C-shape, straight shape, etc.

[0038] SIW 500 may include a third plurality of third via connections 28C extending between the first metal layer 24A and the third metal layer 24C. When viewed in the z-direction, the third via connections 28C may at least partially surround the second slot 30B. The third via connections 28C may be similar to the second via connection 28B described in conjunction with FIG3. In particular, the third via connections 28C and the third metal layer 24C may form an electrical shielding structure or electrical shielding cage that at least partially surrounds the second slot 30B. Figure 5 In the exemplary top view, each of the second via connection 28B and the third via connection 28C can be arranged in a rectangular shape. Figure 5 In a non-limiting case, the first rectangle surrounding the second via connection 28B of the first slot 30A may be narrower relative to the x-direction than the second rectangle surrounding the third via connection 28C of the second slot 30B. This deviation in the dimensions of the two rectangles can be chosen for tuning purposes. However, in another example, the dimensions of the two rectangles may be the same. In particular, the third via connection 28C surrounding the second slot 30B and the second via connection 28B surrounding the first slot 30A may share a common row of via connections. The shared via connection may be arranged between the first slot 30A and the second slot 30B and may extend in the y-direction.

[0039] When measured in the x - direction, the distance between the first slot 30A and the second slot 30B can be approximately equal to λ / 4, where λ is the effective wavelength at the position of at least one of the first slot 30A or the second slot 30B associated with the operating frequency of the RF chip 2. It should be understood that in practice, the distance between the slot 30A and the slot 30B does not have to exactly match the value of λ / 4, but can be optimized or tuned to improve the performance of the RF package and / or suppress the second harmonic of the fundamental band. For example, the distance between the slot 30A and the slot 30B can deviate from λ / 4 by less than about 20% or 15% or 10% or 5% or 4% or 3% or 2% or 1%.

[0040] Now referring to Figure 6 , a top view of the SIW 600 is shown, which can be included in an RF package according to the present disclosure (such as Figure 1 the RF package 100). Figure 6 The SIW 600 of Figure 6 can include some or all of the features of the waveguide previously described. The SIW 600 can include a first slot 30A formed in the first metal layer 24A. In addition, the SIW 600 can include a third slot 30C formed in the first metal layer 24A, where the third slot 30C can be arranged adjacent to the first slot 30A with respect to a direction perpendicular to the propagation direction of the SIW 600 (i.e., with respect to the y - direction). In

[0041] the exemplary top view of Figure 6 , the third slot 30C can be arranged below the first slot 30A.

[0041] In a non - restrictive illustrated example, the first slot 30A can be U - shaped. In additional examples, the first slot 30A can be formed differently (such as V - shaped, C - shaped or straight). The first length l1 of the first part 32 of the first slot 30A can be greater than each of the second length l2 of the second part 34A and the third length l3 of the third part 34B of the first slot 30A, (i.e., l1>l2 and l1>l3). In addition, the first length l1 can be greater than the sum of the second length l2 and the third length l3 (i.e., l1>l2 + l3). Thus, the first part 32 can correspond to the main part of the first slot 30A, which can be arranged perpendicular to the propagation direction of the SIW 600. In addition, in the illustrated case, the second length l2 of the second part 34A can be less than the third length l3 of the third part 34B, i.e., l2<l3. In Figure 6 the example of total , the total length l total of the first slot 30A can be substantially equal to λ / 2, where λ is the effective wavelength at the position of the first slot 30A associated with the second harmonic of the operating frequency of the RF chip 2. That is, in the illustrated example, l total =l1 + l2 + l3≈λ / 2.

[0042] Similar to the first slot 30A, the total length of the third slot 30C is l total It can be substantially equal to λ / 2. In the illustrated example, the shape of the third slot 30C can be similar to that of the first slot 30A. Specifically, the first slot 30A and the third slot 30C can be arranged substantially symmetrically with respect to the x-direction. Alternatively or additionally, the first slot 30A and the third slot 30C can have shapes symmetrical with respect to an axis of symmetry parallel to the x-direction. However, in another example, the shapes of the first slot 30A and the third slot 30C can be different. In one such additional case, the first slot 30A can be U-shaped, while the third slot 30C can be C-shaped, but various other cases are conceivable.

[0043] The first slot 30A can be aligned with the first lobe of the electric field distribution of the SIW 600's TE20 mode, and the third slot 30C can be aligned with the second lobe of the electric field distribution of the SIW 600's TE20 mode. In this context, Figure 7B The diagram illustrates the electric field distribution in the TE20 mode of a waveguide (such as the SIW 600), particularly when viewed in the x-direction. From Figure 7B It can be seen that the electric field distribution can include two lobes, such that the first slot 30A and the third slot 30C can be formed accordingly in the first metal layer 24A. Due to this alignment of the slots 30A and 30C with the lobes of the electric field distribution, the slots 30A and 30C can be configured to suppress the second harmonic of the RF signal transmitted in the SIW 600 at the operating frequency of the RF chip 2. More specifically, the slots 30A and 30C can be configured to suppress the second harmonic of the TE20 mode of the RF signal. (See Figure 3 discussed above.) Figure 5 In the example, the corresponding SIW includes one or more grooves formed in the middle or center of the first metal layer 24A relative to the y-direction. As described above, such a structure can be configured to suppress the second harmonic in the TE10 mode. However, this structure can be transparent to the second harmonic in the TE20 mode. Figure 6 In the example, slots 30A and 30C can be used side-by-side to suppress TE10 and TE20 modes. In this case, the U-shapes of slots 30A and 30C can be asymmetrical to optimize suppression in both modes.

[0044] SIW 600 may include a second plurality of second via connections 28B surrounding the first slot 30A. Furthermore, when viewed in the z-direction, the second via connections 28B may at least partially surround the third slot 30C. That is, both slots 30A and 30C may be surrounded by the second via connections 28B. Similar to the previous example, when viewed in the z-direction, the second via connections 28B may be arranged in a rectangular shape. In the illustrated example, SIW 600 may optionally include a fourth slot 30D and a fifth slot 30E, which may be arranged adjacent to slots 30A and 30C relative to the x-direction. In the illustrated case, the fourth slot 30D may be similar to the first slot 30A, and the fifth slot 30E may be similar to the third slot 30C. Both the fourth slot 30D and the fifth slot 30E may be surrounded by a third plurality of third via connections 28C.

[0045] Now for reference Figures 8A to 8C The diagram illustrates conventional waveguides and waveguides according to this disclosure (particularly such as...). Figure 6 Various insertion losses of the SIW600. Figures 8A to 8C In each of these, the solid line relates to the insertion loss of the waveguide according to this disclosure, while the dashed line relates to the insertion loss of a conventional waveguide.

[0046] Figure 8A The insertion loss of the second harmonic in the TE10 mode is shown, while Figure 8B The insertion loss of the second harmonic in the TE20 mode is shown. The center frequency of the second harmonic can be twice the fundamental band frequency. In the illustrated example, the center frequency of the second harmonic can be around 158 GHz (such as in the exemplary case of the 79 GHz band), as this is suitable for automotive applications. As can be seen from the figure, the waveguide according to this disclosure can suppress both modes better than about 15 dB in the 10 GHz band. That is, as described in conjunction with the previous examples, one or more slots formed in the first metal layer 24A can be configured to suppress the second harmonic of the RF signal transmitted in the waveguide better than about 10 dB in a 10% fractional bandwidth. Here, the fractional bandwidth can be specified as the bandwidth divided by its center frequency. Furthermore, better than 10 dB can specify that the power of the second harmonic can be reduced to 1 / 10 or less.

[0047] Figure 8C The insertion loss at the fundamental frequency band is shown, more specifically near the center frequency of approximately 79 GHz. As can be seen from the figure, the waveguide according to this disclosure can increase the insertion loss by less than about 0.1 dB, which is considered acceptable for most applications. It should be noted that only the TE10 mode is supported at the fundamental frequency, making... Figure 8C Only a single curve for the TE10 mode is shown.

[0048] Figure 9A flowchart illustrating a method for manufacturing an RF device according to this disclosure is shown. This method can be used to manufacture RF devices as discussed above, and therefore can be read in conjunction with any of the foregoing figures. Described in a general manner. Figure 9 This method is used to qualitatively specify aspects of this disclosure. It should be understood that this method may include other aspects. For example, the method may be extended by combining any of the aspects described in conjunction with other examples according to this disclosure.

[0049] At position 36, an RF chip can be formed. At position 38, a coupling element configured to couple RF signals into or out of the RF package can be formed. At position 40, the RF chip and the coupling element can be coupled via the RF signal path. At position 42, a waveguide can be formed in the RF signal path. The waveguide can be disposed inside the RF package and can include a first metal layer and a second metal layer opposite to the first metal layer. At position 44, a first trench can be formed in the first metal layer. The main portion of the first trench can be arranged perpendicular to the propagation direction of the waveguide.

[0050] According to the description, an RF package including the waveguide according to this disclosure can provide a simple and cost-effective way to suppress the second harmonic of the RF signal transmitted in the waveguide, and thus suppress important components of out-of-band radiation. Due to this suppression of out-of-band radiation, EMI / EMC violations can be avoided, and the performance of the corresponding RF package can be improved. In contrast, conventional RF packages require complex and expensive precautions to suppress undesirable out-of-band output. Therefore, the RF package according to this disclosure can outperform conventional RF packages at least in this respect. It should be noted that at least one of the following can be adjusted, tuned, or fine-tuned: the shape of the slot used, the length of the slot used, the arrangement of the via connections around the slot, and the position of the slot relative to the via connections, in order to achieve optimized performance of the RF package including the waveguide, particularly good suppression of the second harmonic of the fundamental frequency band. In this respect, the length of the slot can be considered a primary tuning parameter. Furthermore, the number, arrangement, and shape of the slots used can be determined based on the frequency of the RF signal, the suppression of the TE10 / TE20 modes, and the bandwidth.

[0051] The foregoing description of the examples in this disclosure primarily relates to slots formed in the first metal layer 24A. Alternatively or additionally, in a further example, one or more slots for suppressing second harmonics of RF signals transmitted via the waveguide may be formed in the second metal layer 24B. In this regard, it should be noted that, since the second metal layer 24B is close to the PCB 16 and the electrical connection element 18, the slots of the RF package may preferably be formed in the first metal layer 24A, which is arranged further away from the PCB 16 and the electrical connection element 18.

[0052] The description of the foregoing examples in this disclosure primarily relates to the concept of SIW. However, it should be understood that the description and the aspects described therein are not limited to the concept of SIW, but can also be applied to other waveguide types (such as gas-filled waveguides). That is, in any of the foregoing examples, one or more of the SIWs included can be replaced by another suitable type of waveguide (such as a gas-filled waveguide).

[0053] Example

[0054] The examples described in this article provide RF packaging and methods for manufacturing RF packages.

[0055] Example 1 is a radio frequency (RF) package, including: an RF chip; a coupling element configured to couple an RF signal into or out of the RF package; an RF signal path coupling the RF chip and the coupling element; and a waveguide disposed in the RF signal path, wherein the waveguide is disposed inside the RF package and includes a first metal layer, a second metal layer opposite to the first metal layer, and a first trench formed in the first metal layer, wherein a major portion of the first trench is disposed perpendicular to the propagation direction of the waveguide.

[0056] Example 2 is an RF package of Example 1, wherein the waveguide is a substrate-integrated waveguide and further includes: a dielectric material disposed between a first metal layer and a second metal layer; and a first plurality of first via connections extending between the first metal layer and the second metal layer.

[0057] Example 3 is an RF package of Example 1 or 2, further comprising: a third metal layer disposed above the first metal layer; and a second plurality of second via connections extending between the first metal layer and the third metal layer, wherein the second via connections at least partially surround the first slot when viewed in a direction perpendicular to the first metal layer.

[0058] Example 4 is an RF package of Example 3, wherein when viewed in a direction perpendicular to the first metal layer, the second via connection is arranged in at least two rows on opposite sides of the first slot.

[0059] Example 5 is an RF package of Example 3 or 4, wherein when viewed in a direction perpendicular to the first metal layer, the second via connection extends at least along both sides of the main portion of the first slot.

[0060] Example 6 is an RF package of any of Examples 3 to 5, wherein, when viewed in a direction perpendicular to the first metal layer, the second via connection completely surrounds the first slot.

[0061] Example 7 is an RF package of any of Examples 3 to 6, wherein a second via connection and a third metal layer form an electrically shielded structure that at least partially surrounds the first slot.

[0062] Example 8 is an RF package according to any of the preceding examples, wherein the length of the first slot is substantially equal to λ / 2, where λ is the effective wavelength at the location of the first slot associated with the operating frequency of the RF chip.

[0063] Example 9 is an RF package according to any of the preceding examples, wherein the first slot is configured to suppress the second harmonic of an RF signal transmitted in the waveguide at the operating frequency of the RF chip.

[0064] Example 10 is an RF package according to any of the preceding examples, wherein the first slot is configured to suppress the second harmonic of the RF signal transmitted in the waveguide at the operating frequency of the RF chip better than 10dB in a 10% fractional bandwidth.

[0065] Example 11 is an RF package according to any of the preceding examples, wherein the first slot has a straight shape.

[0066] Example 12 is an RF package of any of Examples 1 to 10, where the first slot is U-shaped or C-shaped.

[0067] Example 13 is an RF package of any of the preceding examples, wherein the first slot is aligned with the lobes of the electric field distribution of the TE10 mode of the waveguide.

[0068] Example 14 is an RF package according to any of the preceding examples, further comprising: a second trench formed in a first metal layer, wherein the second trench is arranged adjacent to the first trench relative to the propagation direction of the waveguide.

[0069] Example 15 is an RF package of Example 14, further comprising: a third plurality of third via connections extending between the first metal layer and the third metal layer, wherein the third via connections at least partially surround the second slot when viewed in a direction perpendicular to the first metal layer.

[0070] Example 16 is an RF package of Example 14 or 15, wherein the third via connection around the second slot and the second via connection around the first slot share a common row of via connections.

[0071] Example 17 is an RF package of any of Examples 14 to 16, wherein the distance between the first and second slots in the waveguide propagation direction is substantially equal to λ / 4, where λ is the effective wavelength at the location of at least one of the first or second slots associated with the operating frequency of the RF chip.

[0072] Example 18 is an RF package of any of Examples 1 to 12, further comprising: a third trench formed in a first metal layer, wherein the third trench is arranged adjacent to the first trench in a direction perpendicular to the propagation direction of the waveguide.

[0073] Example 19 is an RF package of Example 18, wherein the first and third slots are arranged substantially symmetrically to each other with respect to the propagation direction of the waveguide.

[0074] Example 20 is an RF package of Example 18 or 19, wherein the first slot and the third slot have shapes that are symmetrical about an axis of symmetry relative to the direction of waveguide propagation.

[0075] Example 21 is an RF package according to any one of Examples 18 to 20, wherein when viewed in a direction perpendicular to the first metal layer, a second via connection surrounding the first slot at least partially surrounds the third slot.

[0076] Example 22 is an RF package of any of Examples 18 to 21, wherein: the first slot is aligned with the first lobe of the electric field distribution of the TE20 mode of the waveguide, and the third slot is aligned with the second lobe of the electric field distribution of the TE20 mode of the waveguide.

[0077] Example 23 is an RF package according to any of the preceding examples, further comprising: a substrate, wherein: an RF chip is disposed on a first main surface of the substrate, a coupling element is disposed on a second main surface of the substrate opposite to the first main surface, and a waveguide is disposed in the substrate.

[0078] Example 24 is a method for manufacturing an RF package, the method comprising: generating an RF chip; generating a coupling element configured to couple an RF signal into or out of the RF package; coupling the RF chip and the coupling element via an RF signal path; generating a waveguide in the RF signal path, wherein the waveguide is disposed within the RF package and includes a first metal layer and a second metal layer opposite to the first metal layer; and forming a first trench in the first metal layer, wherein a major portion of the first trench is disposed perpendicular to the propagation direction of the waveguide.

[0079] As used in this specification, the terms “connected,” “coupled,” “electrically connected,” and / or “electrically coupled” do not necessarily mean that the components must be directly connected or coupled together. Intermediate components may be provided between “connected,” “coupled,” “electrically connected,” or “electrically coupled” components.

[0080] Furthermore, the terms "over" and "on" used herein to refer to material layers, such as those formed or located "over" or "on" a surface, may be used to mean that the material layer can be "directly on" the implied surface (e.g., formed, deposited, etc.), for example, in direct contact with the implied surface. The terms "over" and "on" used herein to refer to material layers, such as those formed or located "over" or "on" a surface, may also be used to mean that the material layer can be "indirectly on" the implied surface (e.g., formed, deposited, etc.), wherein, for example, one or more additional layers are arranged between the implied surface and the material layer.

[0081] Furthermore, with regard to the use of the terms "having," "containing," "including," "with," or variations thereof in the detailed description or claims, such terms are intended to be inclusive in a manner similar to the term "comprising." That is, as used herein, the terms "having," "containing," "including," "with," "comprising," etc., are open-ended terms that indicate the presence of the stated element or feature but do not exclude additional elements or features. The articles "a," "an," and "the" are intended to include both plural and singular forms unless the context clearly indicates otherwise.

[0082] Furthermore, the terms “exemplary” and “example” are used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as “exemplary” or “example” is not necessarily to be construed as superior to other aspects or designs. Rather, the use of the terms “exemplary” and “example” is intended to present concepts in a specific manner. As used in this application, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless otherwise stated or clearly apparent from the context, “X adopts A or B” is intended to mean either of the natural inclusive substitutions. That is, if X adopts A; X adopts B; or X adopts both A and B, then “X adopts A or B” is satisfied under any of the foregoing examples. Furthermore, the articles “a” and “an” used in this application and the appended claims are generally to be interpreted as meaning “one or multiple” unless otherwise stated or clearly apparent from the context to refer to the singular form. In addition, at least one of A and B generally means A or B or both A and B.

[0083] Although specific examples have been illustrated and described herein, those skilled in the art will understand that various alternatives and / or equivalent embodiments can be used to replace the specific examples shown and described without departing from the scope of the invention. This application is intended to cover any modifications or variations of the specific examples discussed herein. Therefore, the invention is limited only by the claims and their equivalents.

[0084] It should be noted that the methods and apparatuses, including those with preferred embodiments outlined in this document, can be used alone or in combination with other methods and apparatuses disclosed in this document. Furthermore, features outlined in the context of the apparatus also apply to the corresponding methods, and vice versa. Moreover, all aspects of the methods and apparatuses outlined in this document can be combined arbitrarily. In particular, the features of the claims can be combined with each other in any manner.

[0085] It should be noted that the specification and accompanying drawings merely illustrate the principles of the proposed methods and systems. Those skilled in the art will be able to implement various arrangements that, while not explicitly described or shown herein, embody the principles of the invention and are included within the spirit and scope of the invention. Furthermore, all examples and embodiments outlined in this document are primarily intended for illustrative purposes only to aid the reader in understanding the principles of the proposed methods and systems. Moreover, all statements regarding the principles, aspects, and embodiments of the invention provided herein, as well as specific examples thereof, are intended to cover their equivalents.

Claims

1. An RF package, comprising: RF chip (2); The coupling element (4) is configured to couple RF signals into or out of the RF package; RF signal path (6) couples the RF chip (2) and the coupling element (4); as well as A waveguide (8) is arranged in the RF signal path (6), wherein the waveguide (8) is arranged inside the RF package and includes a first metal layer (24A), a second metal layer (24B) opposite to the first metal layer (24A), and a first groove (30A) formed in the first metal layer (24A), wherein the main portion of the first groove (30A) is arranged perpendicular to the propagation direction of the waveguide (8).

2. The RF package according to claim 1, wherein the waveguide (8) is a substrate-integrated waveguide, and further comprises: Dielectric material (26) is disposed between the first metal layer (24A) and the second metal layer (24B), and A first plurality of first via connections (28A) extend between the first metal layer (24A) and the second metal layer (24B).

3. The RF package according to claim 1 or 2, further comprising: A third metal layer (42C) is disposed above the first metal layer (24A); as well as A second plurality of second via connections (28B) extend between the first metal layer (24A) and the third metal layer (24C), wherein when viewed in a direction perpendicular to the first metal layer (24A), the second via connections (28B) at least partially surround the first groove (30A).

4. The RF package of claim 3, wherein when viewed in a direction perpendicular to the first metal layer (24A), the second via connection (28B) is arranged in at least two rows on the opposite side of the first slot (30A).

5. The RF package according to claim 3 or 4, wherein when viewed in a direction perpendicular to the first metal layer (24A), the second via connection (28B) extends at least along both sides of the main portion of the first groove (30A).

6. The RF package according to any one of claims 3 to 5, wherein when viewed in a direction perpendicular to the first metal layer (24A), the second via connection (28B) completely surrounds the first slot (30A).

7. The RF package according to any one of claims 3 to 6, wherein the second via connection (28B) and the third metal layer (24C) form an electrically shielded structure at least partially surrounding the first trench (30A).

8. The RF package according to any one of the preceding claims, wherein the length of the first slot (30A) is substantially equal to λ / 2, where λ is the effective wavelength at the location of the first slot (30A) associated with the operating frequency of the RF chip (2).

9. The RF package according to any one of the preceding claims, wherein the first slot (30A) is configured to suppress the second harmonic of the RF signal transmitted in the waveguide (8) at the operating frequency of the RF chip (2).

10. The RF package according to any one of the preceding claims, wherein the first slot (30A) is configured to suppress the second harmonic of the RF signal transmitted in the waveguide (8) at the operating frequency of the RF chip (2) better than 10 dB in a 10% fractional bandwidth.

11. The RF package according to any one of the preceding claims, wherein the first slot (30A) has a straight shape.

12. The RF package according to any one of claims 1 to 10, wherein the first slot (30A) is U-shaped or C-shaped.

13. The RF package according to any of the preceding claims, wherein the first slot (30A) is aligned with the lobes of the electric field distribution of the TE10 mode of the waveguide (8).

14. The RF package according to any one of the preceding claims further comprises: A second trench (30B) is formed in the first metal layer (24A), wherein the second trench (30B) is arranged adjacent to the first trench (30A) relative to the propagation direction of the waveguide (8).

15. The RF package according to claim 14, further comprising: A third plurality of third via connections (28C) extend between the first metal layer (24A) and the third metal layer (24C), wherein, when viewed in a direction perpendicular to the first metal layer (24A), the third via connections (28C) at least partially surround the second groove (30B).

16. The RF package according to claim 14 or 15, wherein the third via connection (28C) surrounding the second slot (30B) and the second via connection (28B) surrounding the first slot (30A) share a common row of via connections.

17. The RF package according to any one of claims 14 to 16, wherein the distance between the first slot (30A) and the second slot (30B) in the propagation direction of the waveguide (8) is substantially equal to λ / 4, wherein λ is the effective wavelength at the location of at least one of the first slot (30A) or the second slot (30B) associated with the operating frequency of the RF chip (2).

18. The RF package according to any one of claims 1 to 12, further comprising: A third groove (30C) is formed in the first metal layer (24A), wherein the third groove (30C) is arranged adjacent to the first groove (30A) with respect to a direction perpendicular to the propagation direction of the waveguide (8).

19. The RF package according to claim 18, wherein the first slot (30A) and the third slot (30C) are arranged substantially symmetrically with respect to the propagation direction of the waveguide (8).

20. The RF package according to claim 18 or 19, wherein the first slot (30A) and the third slot (30C) have shapes that are symmetrical about an axis of symmetry relative to the propagation direction parallel to the waveguide (8).

21. The RF package according to any one of claims 18 to 20, wherein when viewed in a direction perpendicular to the first metal layer (24A), the second via connection (28B) surrounding the first trench (30A) at least partially surrounds the third trench (30C).

22. The RF package according to any one of claims 18 to 21, wherein: The first slot (30A) is aligned with the first lobe of the electric field distribution of the TE20 mode of the waveguide (8), and The third slot (30C) is aligned with the second lobe of the electric field distribution of the TE20 mode of the waveguide (8).

23. The RF package according to any one of the preceding claims further comprises: Substrate (10), wherein: The RF chip (2) is disposed on the first main surface (12A) of the substrate (10). The coupling element (4) is disposed on the second main surface (12B) of the substrate (10) opposite to the first main surface (12A), and The waveguide (8) is arranged on the substrate (10).

24. A method for manufacturing an RF package, the method comprising: Generate an RF chip (2); A coupling element (4) is generated, the coupling element (4) being configured to couple RF signals into or out of the RF package; The RF chip (2) and the coupling element (4) are coupled via the RF signal path (6); A waveguide (8) is generated in the RF signal path (6), wherein the waveguide (8) is disposed inside the RF package and includes a first metal layer (24A) and a second metal layer (24B) opposite to the first metal layer (24A); and A first groove (30A) is formed in the first metal layer (24A), wherein the main portion of the first groove (30A) is arranged perpendicular to the propagation direction of the waveguide (8).

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