Electromagnetic shielding microelectronic assembly and method for manufacturing the same

Abstract

The present invention provides microelectronic packages, modules, systems and other assemblies containing enhanced electromagnetic (EM) shielding structures, and methods for manufacturing electromagnetic shielding microelectronic assemblies. In one embodiment, the electromagnetic shielding microelectronic assembly includes a first signal path and a second signal path that carry different electrical signals during operation of the microelectronic assembly. The EM shielding structure is positioned between the first signal path and the second signal path. The EM shielding structure also includes a magnetic shielding portion adjacent to (e.g., in contact with and / or directly or indirectly engaged with) the electrical shielding portion. The magnetic shielding portion has a first magnetic permeability and a first electrical conductivity, while the electrical shielding portion has a second magnetic permeability less than the first magnetic permeability and has a second electrical conductivity greater than the first electrical conductivity.

Description

Technical Field

[0001] Embodiments of the present invention relate generally to microelectronics and, more particularly, to microelectronic assemblies containing enhanced electromagnetic shielding structures and to methods for making electromagnetic shielding microelectronic assemblies. Background Art

[0002] EM cross-coupling (more colloquially, "crosstalk") can occur between separate signal paths in microelectronic assemblies, including microelectronic packages, modules, and systems. EM cross-coupling can be particularly problematic in the case of small-size, high-power RF applications. For example, it is envisioned that an RF PA assembly containing a high-gain transistor die is integrated into a package or module having a relatively compact form factor. By common design, the RF PA assembly may include two or more transistor dies attached to a base flange in a side-by-side relationship. The bond wire array may electrically interconnect the transistor die with other circuit elements, such as PA terminals, integrated passive capacitors, or other devices contained in the RF PA assembly. Due to the close proximity of the transistor die and its corresponding bond wire array, EM cross-coupling may occur and, if severe enough, may limit the performance of the microelectronic assembly; for example, EM cross-coupling may replace the impedance presented by the transistor die, which in turn may degrade RF performance in terms of linearity, efficiency, peak power, or gain.

[0003] There is therefore a growing need for microelectronic assemblies (e.g., packages, modules, and systems) that are less susceptible to EM cross-coupling when having a relatively compact form factor and operating at higher RF frequencies or power levels. Ideally, embodiments of such microelectronic assemblies would provide enhanced shielding of both the magnetic and electrical aspects of adjacent signal paths from EM cross-coupling while maintaining a high level of assembly performance and still saving on manufacturing costs. Similarly, it is desirable to provide methods for manufacturing microelectronic assemblies having such desirable features. Other desirable features and characteristics of embodiments of the present invention will become apparent from the subsequent detailed description and the appended claims, in conjunction with the accompanying drawings and the foregoing background technology. Summary of the invention

[0004] According to a first aspect of the present invention, there is provided an electromagnetic shielding microelectronic assembly, comprising:

[0005] a first signal path and a second signal path, the first signal path and the second signal path carrying different electrical signals during operation of the microelectronic assembly; and

[0006] an electromagnetic (EM) shielding structure, the EM shielding structure being positioned between the first signal path and the second signal path, the EM shielding structure comprising:

[0007] a magnetic shield portion having a first magnetic permeability and a first electrical conductivity; and

[0008] An electric shielding portion is adjacent to the magnetic shielding portion, the electric shielding portion having a second magnetic permeability smaller than the first magnetic permeability and having a second electrical conductivity greater than the first electrical conductivity.

[0009] In one or more embodiments, the electromagnetic shielding microelectronic assembly further includes an assembly substrate having a front side, the EM shielding structure protruding from the front side.

[0010] In one or more embodiments, the electromagnetic shielding microelectronic assembly further comprises:

[0011] a first interconnect member through which the first signal path extends, the first interconnect member being bonded to the substrate and located on a first side of the EM shield structure; and

[0012] A second interconnect member through which the second signal path extends is coupled to the substrate and is located on a second, opposite side of the EM shield structure.

[0013] In one or more embodiments, the first interconnect member has a first peak height as taken along a first axis orthogonal to the front side, and wherein the EM shielding structure has a second peak height as taken along a second axis orthogonal to the front side that is equal to or greater than the first peak height.

[0014] In one or more embodiments, the EM shielding structure further comprises a dielectric substrate layer having a first main surface and a second main surface opposite to the first main surface; and

[0015] The magnetic shield portion includes a magnetic shield layer in contact with the first main surface.

[0016] In one or more embodiments, the electric shielding layer includes an electric shielding layer in contact with the second main surface of the dielectric substrate layer.

[0017] In one or more embodiments, the first interconnect member includes a bonding wire bent into a curved shape, and wherein at least one of the magnetic shielding layer and the electric shielding layer is patterned to have a planar geometry corresponding to the curved shape of the bonding wire.

[0018] In one or more embodiments, the electromagnetic shielding microelectronic assembly further includes a ground conductor connected to the electrical shielding portion and coupling the electrical shielding portion to an electrical ground.

[0019] In one or more embodiments, the magnetic shield portion includes a coating composed of a magnetically permeable material and formed over an outer surface of the electrical shield portion.

[0020] In one or more embodiments, the electrical shielding portion comprises a conductive core.

[0021] In one or more embodiments, the electromagnetic shielding microelectronic assembly further comprises:

[0022] a substrate having a front side;

[0023] a first bond wire coupled to the front side and through which the first signal path extends; and

[0024] A microelectronic device over which the first bond wires extend, the microelectronic device being at least partially covered by the EM shielding structure as taken along an axis orthogonal to the front side.

[0025] In one or more embodiments, the electromagnetic shielding microelectronic assembly further includes a second bond wire coupled to the front side and the second signal path extending through the second bond wire;

[0026] Wherein the EM shielding structure further comprises:

[0027] a body positioned between the first joining line and the second joining line; and

[0028] A shielding wing protrudes from the body over at least a portion of the microelectronic device.

[0029] In one or more embodiments, the electromagnetic shielding microelectronic assembly further includes a radio frequency power amplification circuit;

[0030] The first signal path and the second signal path include a first amplifier path and a second amplifier path, respectively, and the first amplifier path and the second amplifier path are included in a radio frequency power amplification circuit.

[0031] According to a second aspect of the present invention, there is provided an electromagnetic shielding microelectronic assembly, comprising:

[0032] a first signal path and a second signal path, the first signal path and the second signal path carrying different electrical signals during operation of the electromagnetically shielded microelectronic assembly;

[0033] a first interconnect member, the first signal path extending through the first interconnect member;

[0034] a second interconnect member, the second signal path extending through the second interconnect member;

[0035] a substrate having a front side to which the first and second interconnect members are coupled; and

[0036] An electromagnetic (EM) shielding structure, the EM shielding structure comprising:

[0037] a shield substrate protruding from the front side of the substrate at a position between the first interconnect member and the second interconnect member; and

[0038] A patterned magnetic shielding layer, in contact with the first major surface of the shielding substrate and composed of a magnetically permeable material, is configured to reduce EM cross-coupling between the first signal path and the second signal path during operation of the electromagnetically shielded microelectronic assembly.

[0039] In one or more embodiments, the EM shielding structure further includes a patterned electric shielding layer bonded to a second opposing major surface of the shielding substrate opposite to the patterned magnetic shielding layer.

[0040] In one or more embodiments, the shielding substrate is composed of a dielectric material, and wherein the patterned electrical shielding layer is electrically grounded.

[0041] In one or more embodiments, the magnetically permeable material has a first magnetic permeability and a first electrical conductivity, and wherein the shielding substrate is composed of a material having a second magnetic permeability less than the first magnetic permeability and a second electrical conductivity greater than the first electrical conductivity.

[0042] In one or more embodiments, the first interconnect member includes a bond wire having an arcuate bond wire profile, and wherein the patterned magnetic shield layer is patterned to have an arcuate planar geometry substantially corresponding to the arcuate bond wire profile.

[0043] According to a third aspect of the present invention, there is provided an electromagnetic shielding microelectronic assembly, comprising:

[0044] a first signal path and a second signal path, the first signal path and the second signal path carrying different electrical signals during operation of the electromagnetically shielded microelectronic assembly;

[0045] a first bond wire through which the first signal path extends;

[0046] a second bond wire through which the second signal path extends; and

[0047] An electromagnetic (EM) shielding structure is between the first bond wire and the second bond wire, the EM shielding structure being at least partially composed of a magnetically permeable material and configured to reduce magnetic cross coupling between the first bond wire and the second bond wire during operation of the EM shielding microelectronic assembly.

[0048] In one or more embodiments, the EM shielding structure comprises:

[0049] a conductive core; and

[0050] A magnetically permeable coating is formed around the core.

[0051] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] At least one example of the present invention will be described below in conjunction with the accompanying drawings, wherein like reference numerals represent like elements, and:

[0053] Figure 1 is a diagram of a core magnetic component showing EM cross-coupling between adjacent signal paths in a microelectronic assembly (partially shown) containing an electrical shielding structure as depicted in accordance with the teachings of the prior art;

[0054] Figure 2 is a diagram of a microelectronic assembly (partially shown) containing an enhanced EM shielding structure that minimizes EM cross-coupling between separate or discrete signal paths as depicted in accordance with an exemplary embodiment of the present disclosure;

[0055] Figure 3 is a schematic diagram of a microelectronic assembly (here, an RF PA package) containing one or more EM shielding structures as shown in accordance with a general embodiment of the present disclosure;

[0056] Figure 4 is an isometric view of two adjacent interconnect members (here, adjacent bond wire arrays) separated by an intervening EM shielding structure including a continuous, non-patterned electrical and magnetic shielding layer as shown in accordance with an exemplary embodiment of the present disclosure;

[0057] Figure 5 Graphically depicts the performance of a microelectronic assembly having an electrical shielding structure and having no shielding structure. Figure 4 Simulated improvements in gain, cross-coupling, and isolation achieved by the EM-shielded microelectronic assembly shown in;

[0058] Figure 6 and 7As shown in another exemplary embodiment according to the present disclosure, a patterned magnetic shielding layer ( Figure 6 ) and patterned electrical shielding layer ( Figure 7 ) isometric view of an array of adjacent bond wires separated by an intervening EM shielding structure (e.g., a core dielectric layer);

[0059] Figure 8 Shown in Figures 6 to 7 The plane between the adjacent bonding wire arrays shown in FIG. 1 is modeled and suitable for determining Figure 6 A magnetic flux concentration curve diagram of the shape, arrangement and / or thickness distribution of the patterned magnetic shielding layer shown in;

[0060] Fig. 9 is an isometric view of an array of contiguous bond wires separated by an intervening EM shielding structure in the form of a coated wire fence as shown in accordance with another exemplary embodiment of the present disclosure;

[0061] Fig.10 This more clearly shows the penetration of the conductive wire core and the magnetically permeable coating within the wire fence. Fig. 9 A cross-sectional view taken from the coated wire fence shown in ;

[0062] Fig.11 is an isometric view of an array of adjacent bond wires separated by an intervening EM shield structure including lateral extensions or wings covering a microelectronic device (e.g., an integrated capacitor) over which the bond wire arrays extend, as depicted in accordance with yet another exemplary embodiment; and

[0063] Fig.12 As shown in another exemplary embodiment according to the present disclosure, Figure 4 , 6 , 7 and 11, and in particular, a top view of a large-scale MIMO system including multiple EM shielding structures.

[0064] For the sake of simplicity and clarity of explanation, descriptions and details of well-known features and technologies may be omitted to avoid unnecessary confusion of the exemplary and non-limiting embodiments of the present invention described in the subsequent detailed description. It should be further understood that unless otherwise stated, the features or elements appearing in the drawings are not necessarily drawn to scale. For example, the size of certain elements or regions in the drawings may be enlarged relative to other elements or regions to improve the understanding of the embodiments of the present invention. DETAILED DESCRIPTION

[0065] The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application or uses of the invention. The term "exemplary" as it appears throughout this article is synonymous with the term "example" and is used repeatedly below to emphasize that the following description only provides multiple non-limiting examples of the present invention and should not be construed in any way as limiting the scope of the present invention, as stated in the claims.

[0066] abbreviation

[0067] The following abbreviations appear throughout this document:

[0068] Cu-copper;

[0069] EM - electromagnetic or electromagnetically;

[0070] Fe - iron;

[0071] GaN gallium nitride;

[0072] MIMO-Multiple Input Multiple Output (antenna structure);

[0073] PA-power amplifier;

[0074] RF - radio frequency; and

[0075] μ r -Relative (magnetic) permeability.

[0076] definition

[0077] The following definitions apply throughout this document.Those terms not expressly defined here or elsewhere herein are given their ordinary meaning in the relevant technical field.

[0078] Conductive material - a material having a resistivity of less than 1 milliohm-mm at 20 degrees Celsius (°C).

[0079] Electromagnetic shielding microelectronic assembly—a microelectronic assembly (defined below) that includes at least one electromagnetic (EM) shielding structure that reduces magnetic and electrical cross-coupling between signal paths during operation of the assembly.

[0080] Interconnect member—an electrical conductor contained in a microelectronic assembly or a group of electrical conductors that electrically connects two or more contacts, such as terminals or bond pads.

[0081] Magnetic permeability materials - have a relative magnetic permeability (μ) exceeding 1000 r ) materials.

[0082] Microelectronic assembly—a general term used to broadly cover microelectronic packages, modules, systems, and other articles of manufacture containing microelectronic circuits.

[0083] Mu Metal - any alloy consisting essentially of nickel (Ni) and Fe by weight and having a relative magnetic permeability in excess of 1000.

[0084] Relative magnetic permeability (μ r ) - The magnetic permeability (μ) of a material or medium relative to the magnetic permeability (μ) of free space 0 ) ratio.

[0085] Superconducting magnetic alloy - an alloy consisting mainly of Ni, Fe and molybdenum (Mo) by weight and having a relative magnetic permeability exceeding 1000.

[0086] Overview

[0087] As discussed above, the performance of microelectronic packages, modules, systems, and other microelectronic assemblies can be limited in certain circumstances by EM cross-coupling. EM cross-coupling occurs due to interference between EM domains generated when currents containing signals are directed through different or separate signal paths contained within the EM assembly. EM cross-coupling can be particularly problematic in certain applications, such as when signal paths are in close proximity (e.g., due to the relatively compact form factor of the assembly) and the assembly is operated at higher RF frequencies and / or power levels. Microelectronic assemblies containing high frequency RF circuits, such as RF PA packages and modules, are often particularly susceptible to EM cross-coupling.

[0088] To date, industry efforts have focused on addressing EM cross-coupled electrical components, with substantially no addressing of EM cross-coupled magnetic components. As a result, conventional electrical shielding structures are typically in the form of a monolithic or single-layer wall composed of a material having relatively high electrical conductivity and low magnetic permeability, such as Cu. While potentially reducing electrical cross-coupling, such conventional electrical shielding structures have minimal impact on EM cross-coupled magnetic components, and thus provide an incomplete solution to large-scale reduction or prevention of EM cross-coupling. At the same time, conventional electrical shielding structures may degrade the performance of microelectronic assemblies in other ways. For example, the provision of such electrical shielding structures typically results in the embedding of a relatively large body of conductive material within the induced EM domain, which may result in eddy current losses, hysteresis effects, exacerbation of RF mismatch (where applicable), and other problems.

[0089] In addition, the above concepts are emphasized. Figure 1 A limited portion of a conventional electrically shielded microelectronic assembly 20 is diagrammatically shown. The depicted portion of the microelectronic assembly 20 includes two signal paths 22, 24 that protrude into and out of the plane of the page. The signal paths 22, 24 are formed in part by (and therefore extend through) interconnects or bond wires 26, 28, respectively, as shown in FIG. Figure 1As shown in the cross section in FIG. 2 , the bonding wires 26 and 28 extend relatively close to each other for a distance. When the current carrying the signal (I 1 , I 2 ) is guided along the signal paths 22, 24 and thus conducted through the bonding wires 26, 28, a corresponding magnetic field is generated around the bonding wires 26, 28 in a vector orthogonal to the current. The corresponding core of the magnetic field is at Figure 1 The 1 ” and “H 2 It should be appreciated that the induced magnetic field may extend well beyond the dashed circles 30, 32, such that the magnetic field induced by passing current through the bond wire 26 may impinge on the adjacent bond wire 28 and the magnetic field induced by passing current through the bond wire 28 may impinge on the adjacent bond wire 26, thereby potentially causing EM interference or cross-coupling as described below.

[0090] The signal paths 22, 24 carry separate or distinct electrical signals during operation of the microelectronic assembly 20. The signals carried by the signal paths 22, 24 may be digital signals, analog signals, or a combination thereof. Regardless of the signal type or types in question, EM cross-coupling may occur between the signal paths 22, 24 due to the relatively close proximity of the bonding wires 26, 28 depending on the operating parameters of the assembly 20; for example, as described above, EM cross-coupling may be problematic in high frequency (e.g., RF) applications. According to conventional methods involving electrical aspects of reducing EM cross-coupling, an intervening electrical shielding structure 34 (hereinafter, "electrical shield 34") may be positioned between the bonding wires 26, 28. When the electrical shield 34 is provided, the electrical shield 34 may be in the form of a single piece or single layer wall composed of a material having a relatively high electrical conductivity and a relatively low magnetic permeability (e.g., Cu). While the electrical cross-coupling between the signal paths 22, 24 may be reduced, the electrical shield 34 does little to reduce the core magnetic field (H 1 , H 2 ) between the magnetic cross coupling. In contrast, due to the low magnetic permeability of the electric shield 34, the core magnetic field (H 1 , H 2 ) can freely pass through the body of the shield 34 and intermingle or overlap with each other in the interference zone 36, as illustrated. When the core magnetic field (H) induced by passing current through the first signal path of the signal paths 22, 24 1 , H 2) becomes sufficiently wide or bulky to impinge on the other of the signal paths 22, 24, such impingement may alter the signal characteristics causing EM cross-coupling. In other words, the EM domain induced by passing an electrical signal through one of the signal paths 22, 24 may cause EM interference directly attributable to the impingement of an EM domain overlapping the domain induced by passing another electrical signal through the other of the signal paths 22, 24, and vice versa. Excessive magnetic cross-coupling, and more generally, EM cross-coupling, may thus occur, thereby limiting the performance of the assembly 20 in the manner previously described.

[0091] See instead Figure 2 , a diagram showing a limited portion of an EM shielding microelectronic assembly 38 according to an exemplary embodiment of the present disclosure. In a broad sense, the EM shielding microelectronic assembly 38 is similar to Figure 1 20. Likewise, the EM shielded microelectronic assembly 38 includes two signal paths 40, 42 that carry different or unique electrical signals during operation of the assembly 38. The signal paths 40, 42 extend through interconnect members 44, 46 that protrude into and out of the page. Figure 2 As shown in the cross-section in FIG. 1 , the interconnect members 44, 46 may be bonding wires, metal (e.g., Cu) traces, or any other type of conductive element. The interconnect members 44, 46 extend a distance relatively close to each other. When the current carrying the signal (I 1 , I 2 ) passes through the interconnecting members 44, 46 and is directed along the signal paths 40, 42, a magnetic field is generated. As in the previous case, the magnetic field (H 1 , H 2 ) has an outer boundary at Figure 2 It should also be noted that for the sake of clarity, the induced magnetic field (H 1 , H 2 ) is shown in Figure 2 middle.

[0092] Continue to refer to the EM shielded microelectronic assembly 38 ( Figure 2 ), and compared to the electrically shielded microelectronic assembly 20 ( Figure 1 ), the intervening EM shielding structure 52 is positioned between the interconnect members 44, 46, and therefore, between the signal paths 40, 42. Due to the characteristics of the EM shielding structure 52, the core magnetic field (H 1 , H 2) does not extend significantly beyond the EM shield structure 52 to impinge on the interconnect members 44 and / or the interconnect members 46 located on the opposite side of the shield structure 52 (or does so only to a very limited extent). The EM shield structure 52 is at least partially composed of a magnetically permeable material that concentrates the magnetic flux within the layer 56 of the structure 52 to confine the core magnetic field (H 1 , H 2 ) range and overlap. The EM shielding structure 52 may take any form suitable for reducing magnetic cross coupling and, more generally, EM cross coupling between the interconnect members 44, 46 in this manner. For example, in certain embodiments, the EM shielding structure 52 may take a form similar to the electrical shield 34 ( Figure 1 ) but in the form of a monolithic wall or structure made of a material having a relatively high magnetic permeability. In more complex embodiments, and as Figure 2 As depicted in EM shield structure 52, includes at least one electrical shield portion or layer 54 engaged with (or in contact with or in proximity to) at least one magnetic shield portion or layer 56, as discussed more fully below.

[0093] For the first layer 54 of the EM shielding structure 52, the electric shielding layer 54 is composed of a material having a higher electrical conductivity and a lower magnetic permeability than the magnetic shielding layer 56. In an embodiment, the electric shielding layer 54 is composed of a metal material having an electrical conductivity of less than 1 milliohm millimeter at 20°C. Suitable materials include, but are not limited to, alloys containing one or more of the following as main components by weight: Cu, Ni, aluminum (Al), silver (Ag), and gold (Au). As yet another possibility, the electric shielding layer 54 may be composed of a material having medium electrical conductivity and magnetic permeability properties. As in Figure 2 As indicated by reference numeral 58, the electrical shielding layer 54 may be electrically grounded, for example, to reduce eddy current losses, hysteresis effects, and RF mismatch (where applicable). In other embodiments, the layer 54 may not be electrically grounded.

[0094] Magnetic shielding layer 56 may be composed of any magnetically permeable material (or combination of magnetically permeable materials) having a magnetic permeability greater than that of electrical shielding layer 54 and an electrical conductivity less than that of layer 54. As presented herein, when the relative magnetic permeability (μ r ) exceeds the relative magnetic permeability (μ) of another material r ) is at least 1%, a specific material (e.g. Figure 2 In the example of the magnetic shielding layer 56 formed of the material) is considered to have a greater Figure 2) is the magnetic permeability of the material from which the electric shielding layer 54 is formed in the example. Similarly, a particular material (e.g., the material from which the magnetic shielding layer 56 is formed) is considered to have a conductivity less than another material (e.g., the material from which the electric shielding layer 54 is formed) when the particular material has a resistivity at least 1% greater than the resistivity of the other material at 20°C. The foregoing definitions apply throughout this document. In addition, typically, relatively large differences will exist between the corresponding magnetic permeabilities and electrical conductivities of one or more magnetic shielding layers and one or more electric shielding layers included in a given EM shielding structure. Therefore, in an embodiment, the magnetic permeability of the magnetic shielding layer 56 will be at least 50% higher than the magnetic permeability of the electric shielding layer 54, and preferably at least twice the magnetic permeability of the electric shielding layer 54. Additionally or alternatively, in an embodiment, the electrical conductivity of the electric shielding layer 54 may be at least 50% higher than the electrical conductivity of the magnetic shielding layer 56, if not twice the electrical conductivity of the magnetic shielding layer 56. In still other embodiments, the respective magnetic and electrical permeabilities of the layers 54, 56 may vary by greater or lesser amounts.

[0095] Continue to view Figure 2 In some embodiments, each magnetic shield layer 56 may be composed of a magnetic material having a relative magnetic permeability (μ r ) of one or more materials. Suitable materials include, but are not limited to, metallic materials including Mu metal, Fe-based alloys (e.g., permalloy), ferrites, electrical steels, amorphous metal alloys, and other alloys with relatively high magnetic permeability. Composite materials containing magnetically permeable particles, fibers, or the like may also be used in embodiments. For example, in certain embodiments, the magnetic shielding layer 56 may be made of a molded material (e.g., an injection molded polymer) containing particles composed of ferrite, Fe, Mu metal, or another magnetically permeable material. Due to the relatively high magnetic permeability of the magnetic shielding layer 56, the magnetic flux is concentrated within the layer 56 and is primarily guided through the layer 56, rather than freely passing through the structure 52, to prevent the core magnetic field (H 1 , H 2 ) impinges upon components 44, 46 on opposite sides of structure 52. Thus, if any magnetic cross coupling occurs during operation of the assembly, it is relatively minimal. Thus, in combination, electrical shielding layer 54 and magnetic shielding layer 56 provide comprehensive and highly effective protection against EM cross coupling that may otherwise occur during operation of microelectronic assembly 38.

[0096] Figure 2 The teachings of are effectively applied to EM shielding structures at the package level, module level, system level or other overall levels. In addition, Figure 2The illustrated EM shielding structure 52 and other EM shielding structures disclosed herein may be positioned between any conductive components or circuit elements through which separate or distinct (e.g., electrically parallel) signal paths extend. A non-exhaustive list of such components includes active microelectronic devices (e.g., semiconductor and microelectromechanical systems (MEMS) dies), passive microelectronic devices (e.g., surface mount devices (SMDs) and integrated passive devices), and interconnect members, such as interconnect wires (e.g., metal traces), wire bonds, and other such members for electrical interconnection purposes. Several exemplary embodiments of EM shielding structures positioned between arrays of bond wires are described in detail below. Figures 4 to 11 First, however, with Figure 3 An exemplary description is provided in conjunction with a microelectronic package of a device in which one or more EM shielding structures may be incorporated. Although the following, additional embodiments of the EM shielding structure may be incorporated into a module and system (as described below with reference to Fig.12 In combination with various other types of microelectronic assemblies of the type discussed elsewhere).

[0097] Go to Figure 3 , schematically depicts an electromagnetic shielding circuit structure 60 (hereinafter, “EM shielding circuit 60”) according to an exemplary embodiment of the present disclosure. The EM shielding circuit 60 is effectively integrated into a microelectronic assembly, such as Figure 3 . In this particular example, the microelectronic package 62 takes the form of a leaded air cavity package; however, in alternative embodiments, the microelectronic package 62 may take a variety of other forms, such as a leadless package or a molded package with different lead types. The functionality provided by the EM shielded circuit 60 will vary widely among embodiments as needed to meet the needs of a particular application or use; however, by way of non-limiting example, the circuit 60 may provide RF PA functionality in one possible embodiment, and the microelectronic package 62 may take the form of an N-way PA implemented with one or more (i.e., N) high-gain transistor dies (such as laterally-diffused metal-oxide-semiconductor (LDMOS), GaN, or gallium arsenide (GaAs) transistors) arranged in N parallel amplification paths.

[0098] The EM shield circuit 60 includes a first signal path 63 and a second signal path 65 that extend at least partially through the circuit 60 and carry electrical signals in parallel during circuit operation. The signal paths 63, 65 can extend through the entire microelectronic package 62 and, therefore, extend between input / output (I / O) terminals (leads or pins) of the microelectronic package 62. Specifically, the signal path 63 can extend from an input terminal 66 of the circuit 60 to an output terminal 68, which can correspond to an input conductor 70 and an output lead 72 of the microelectronic package 62, respectively, as shown in FIG. Figure 3 Similarly, signal path 65 can extend from input terminal 74 of circuit 60 to output terminal 76, which can correspond to input lead 78 and output lead 80, respectively, of microelectronic package 62. In additional embodiments, circuit 60 can include a different number of signal paths, input terminals, and output terminals, or can be varied in other ways relative to the example shown.

[0099] like Figure 3 , at least one microelectronic device 82 is positioned in the signal path 63 and electrically interconnected between the terminals 66, 68 of the circuit 60. The microelectronic device 82 may be, for example, an integrated circuit carrying a semiconductor die, such as an RF circuit; for example, an RF power transistor having a control (input) terminal electrically connected to the input terminal 66 and a terminal carrying a current (output), the control terminal being electrically connected to the input terminal 66, and the current carrying terminal being electrically connected to the output terminal 68. Selected terminals of the microelectronic device 82, such as bonding pads, may be electrically coupled to the circuit input terminal 66 by one or more interconnect members 84. The interconnect members 84 may take the form of, for example, patterned metal (e.g., Cu, Al, or Au) traces, three-dimensional (e.g., inkjet) printed traces, bond wires, vias, or various other conductive structures. Similarly, other terminals of the microelectronic device 82 are electrically coupled to the circuit output terminal 68 by one or more interconnect members 86, which may likewise be bond wires, metal traces, or other electrical conductors for interconnect purposes.

[0100] In an embodiment, the microelectronic device 82 may be directly interconnected to either or both of the terminals 66, 68. Alternatively, and as Figure 3As indicated by reference numeral 88 in the figure, any number of intervening microelectronic devices and interconnect members may be additionally disposed in the signal path 63 between the terminals 66, 68. For example, in one implementation of the circuit 60, the microelectronic device 82 is in the form of an active semiconductor die, such as an RF semiconductor power transistor die, which is directly connected to the terminals 66, 68 via interconnect members 84, 86 in the form of bond wires or bond wire arrays. In such embodiments, the RF semiconductor die may be additionally electrically coupled to an electrical ground via a conductive substrate or base flange 100 also contained in the package 62, such as Figure 3 . Alternatively, in other embodiments, the microelectronic device 82 may not be directly connected to the terminals 66, 68, but instead electrically coupled to one or more passive devices, such as SMDs or integrated passive devices (e.g., capacitor structures), which are otherwise contained or integrated within the microelectronic package 62. Any such passive device may be electrically coupled to the terminals 66, 68 to then complete the desired circuit structure. Many other circuit architectures are also possible, with the circuit 60 appropriately containing any number and type of active devices (e.g., semiconductor die and MEMS die), passive devices (e.g., integrated passive devices and SMDs), and other such devices (e.g., RF antennas or shielding structures) electrically interconnected between the terminals 66, 68 to form the signal path 63 as desired.

[0101] In the shown Figure 3, the circuit elements defining the second signal path 65 of the circuit 60 are similar or identical to the circuit elements defining the first signal path 63. Thus, as in the previous case, at least one microelectronic device 102 (e.g., a semiconductor die) is electrically coupled (whether directly or indirectly) to the circuit input terminal 74 via a first interconnect member 104 (e.g., a first bond wire array). The microelectronic device 102 is additionally electrically coupled (either directly or indirectly) to the circuit output terminal 76 via a second interconnect member 106 (e.g., a second bond wire array). Likewise, and as schematically indicated by reference numeral 108, any number and type of additional microelectronic devices and interconnect members may likewise be disposed between the microelectronic device 102 and the terminals 74, 76 to form a desired circuit structure. For example, in an embodiment in which the microelectronic package 62 takes the form of a dual-path RF power amplifier, the microelectronic devices 82, 102 may be high power (e.g., LDMOS or GaN) transistor dies, and one or more sets of integrated capacitors may be electrically interconnected between the devices 82, 102 and the corresponding circuit terminals 66, 68, 74, 76. In such an embodiment, one of the signal paths 63, 65 may be formed by a peaking transistor element of a Doherty PA or other multipath amplifier, while the other of the signal paths 63, 65 is formed by a carrier transistor element of a Doherty PA or other multipath amplifier. In addition, many other circuit layouts are possible in further embodiments, wherein Figure 3 The schematic diagrams are provided by way of non-limiting example only.

[0102] Due to the relatively close physical spacing of the conductive circuit elements defining the circuit path 63 (i.e., the input terminal 66, the interconnect member 84, the microelectronic device 82, the interconnect member 86, and the output terminal 68) and the conductive circuit elements defining the parallel circuit path 65 (i.e., the input terminal 74, the interconnect member 104, the microelectronic device 102, the interconnect member 106, and the output terminal 76), EM cross-coupling may occur during operation of the circuit 60. Depending on its severity, the EM cross-coupling may degrade certain aspects of the circuit performance and, more generally, the overall performance of the microelectronic package 62. For example, the EM cross-coupling, and more specifically, the magnetic components of the EM cross-coupling, may displace the impedance presented by the transistor die (e.g., the devices 82, 102), which in turn may limit the RF performance in terms of linearity, efficiency, peak power, gain, or any combination thereof (where applicable). The EM cross-coupling may generally occur when the induced EM domain extends over the primary EM interference region 110 between the parallel circuit paths 63, 65. Specifically, it has been determined that in at least some embodiments of the circuit 60, undesired EM cross-coupling may be problematic when the cross-location region 112 impinges upon an opposing one of the interconnect members 84, 104 and / or an opposing one of the interconnect members 86, 106. The undesired EM cross-coupling may adversely cause an impact on the performance of the circuit 60; for example, in circuit terms, mutual inductance or mutual capacitance may generate and alter currents and voltages of signals conducted through the circuit paths 63, 65.

[0103] To reduce EM cross-coupling during operation of the circuit 60 and package 62, a single elongated EM shielding structure 114 may be positioned in the primary EM interference region 110 between the circuit elements defining the signal paths 63, 65. In various embodiments, the EM shielding structure 114 may take the form of a wall, fin, or separate strip composed of a magnetically permeable material such as Mu metal, Permalloy, or ferrite, possibly joined or bonded to (or positioned in abutting relation or in close proximity to) another strip or wall of a conductive material of the type previously discussed. For example, in certain embodiments, the EM shielding structure 114 may have a substantially uniform EM cross-coupling pattern. Figure 2104. In embodiments, the EM shielding structure 114 may extend the entire length of (and possibly slightly beyond) the primary EM interference zone 110. In other embodiments, a plurality of smaller EM shielding structures 116 may be positioned in a more targeted manner in positioning areas (including, but not limited to, area 112) between adjacent groups of interconnected components; for example, a first structure 116 may be positioned between components 84, 104, and a second structure 116 may be positioned between components 86, 106. As yet another possibility, a combination of these approaches may be used such that a relatively overlong EM shielding structure may extend the length of region 110, while in positioning areas 112 the magnetic isolation characteristics of the shielding structure may be enhanced by, for example, providing an increased volume of magnetically permeable material in these areas. Figures 4 to 11 Several exemplary embodiments of EM shielding structures are discussed in conjunction. In particular, the shielding structures described below can be used in various combinations in the embodiments of the EM shielding microelectronic package 62 and other EM shielding microelectronic assemblies described herein, including the various combinations described below with reference to FIG. Fig.12 With this in mind, the exemplary embodiments described below are not mutually exclusive unless otherwise stated.

[0104] First, for Figure 4 The exemplary embodiment shown in , depicts a restricted portion of an EM shielded microelectronic assembly 118 according to an exemplary embodiment of the present disclosure. The microelectronic assembly 118 includes at least two separate signal paths 123, 125, which extend in parallel (in an electrical sense, and possibly in a spatial or geometric sense) through the illustrated portion of the assembly 118. In addition, the microelectronic assembly 118 includes a first interconnect member 120 and a second interconnect member 122, and the signal paths 123, 125 extend through the first interconnect member 120 and the second interconnect member 122. In this example, the interconnect members 120, 122 are illustrated as bonding wire arrays, and will therefore be referred to as "bonding wire arrays 120, 122" respectively below. In other embodiments, the bonding wire arrays 120, 122 may each be replaced by a single bonding wire or a different type of electrical conductor (such as one or more metal traces). In an embodiment, the microelectronic assembly 118 may correspond to Figure 3 1. The microelectronic package 62 is shown in FIG. 1, in which case the signal paths 123, 125 may correspond to the signal paths 63, 65, while the interconnect members 120, 122 correspond to the interconnect members 84, 104 or the interconnect members 86, 106, respectively.

[0105] The bonding wire array 120 includes a plurality of bonding wires 124. Figure 4The lateral axis in (corresponding to the X-axis identified by the coordinate legend 142) is arranged in grouped intervals or row intervals. The bonding wires 124 each extend between two points of a contact (here, bonding pads 126, 128) disposed on the upper major surface or front side 131 of the assembly substrate 130. Similarly, the bonding wire array 122 includes a plurality of bonding wires 132 that are arranged in rows and extend between bonding pads 134, 136 that are further disposed on the front side 131 of the substrate 130. The bonding pads 126, 128, 134, 136 and the substrate 130 are provided by way of example only, and it should be understood that the bonding wire arrays 120, 122 may extend between and electrically connect various different types of terminals or contacts. For example, in an alternative embodiment, the bonding wire arrays 120, 122 may each extend from a semiconductor die or other microelectronic device (e.g., Figure 3 The bonding pads on the devices 82, 102 shown in FIG. 1 extend to bonding pad racks or other dedicated contacts within a microelectronic package, module, or system. The assembly substrate 130 may be a flange, a printed circuit or wiring board, or any other supporting body that may or may not contain electrical wiring components. In addition, Figure 4 While only a limited area of ​​the substrate 130 is depicted in FIG. 1 , it should be noted that the EM shielding microelectronic assembly 118 will additionally include various other circuit elements and interconnect members that are not shown for the sake of clarity of illustration.

[0106] A wall-like EM shielding structure 138 is disposed between the bond wire arrays 120, 122, wherein the arrays 120, 122 are located on opposite sides of the structure 138. The EM shielding structure 138 physically separates or divides the arrays 120, 122 as viewed along a lateral axis (corresponding to the X-axis of the coordinate legend 142) parallel to the substrate front side 131. In the example shown, the EM shielding structure 138 includes at least two separate portions or regions: (i) an electrical shielding portion or layer 140, and (ii) a magnetic shielding portion or layer 141. The electrical shielding layer 140 and the magnetic shielding layer 141 may be in the form of continuous or non-patterned layers, joined or otherwise bonded to form a double wall. In other embodiments, the electrical shielding layer 140 and the magnetic shielding layer 141 may not be directly joined, but instead may be positioned adjacent to each other as viewed along the lateral axis, and may be in physical contact; for example, the shielding layers 140, 141 may be pressed or clamped together in some manner.

[0107] The magnetic shielding layer 140 may be made of a magnetically permeable material such as Mu metal, Fe alloy (e.g., Permalloy), electrical steel, or other materials described herein. Alternatively, the magnetic shielding layer 141 may be made of a composite material containing magnetically permeable (e.g., Fe or ferrite) particles or other fillers or a relative magnetic permeability (μ) greater than 1000 and more preferably greater than 10,000. r). In other embodiments, layer 141 may be composed of a material having a magnetic permeability equal to or greater than 80,000 Henrys per meter. Relatively speaking, the electric shielding layer 140 may be composed of any material having a greater electrical conductivity than the magnetic shielding layer 141 and a smaller magnetic permeability than the layer 140. In addition, in an embodiment, if the electrical conductivity of the material of the electric shielding layer 140 is not at least twice the electrical conductivity of the material constituting the magnetic shielding layer 141, then the electric shielding layer 140 may be composed of a material having an electrical conductivity at least 50% higher than the electrical conductivity of the material constituting the magnetic shielding layer 141; and if the magnetic permeability of the magnetic shielding layer 141 is not at least twice the magnetic permeability of the material constituting the electric shielding layer 140, then the magnetic shielding layer 141 may be composed of a material having a magnetic permeability at least 50% higher than the magnetic permeability of the material constituting the electric shielding layer 140. A non-exhaustive list of suitable materials for forming all or a portion of the electrical shield 140 includes metals and alloys containing Cu, Ni, Al, Au, Ag, or any combination thereof as a major component by weight. Figure 4 14, the electrical shielding layer 140 may be coupled to an electrical ground, for example, by a grounding conductor 143 (such as a metal trace, plated through hole, or ground plane), as indicated by reference numeral 145. Grounding of the electrical shielding layer 140 may help reduce any eddy current losses during operation of the assembly 118 and provide other performance benefits, as discussed below. In other embodiments, the electrical shielding layer 140 may not be grounded.

[0108] The size, composition, and configuration of the EM shield structure 138 will vary among embodiments and may be adapted to provide a desired level of magnetic shielding between the bond wire arrays 120, 122 and, more generally, the various signal paths 123, 125. In at least some embodiments, the EM shield structure 138 may extend along the Y-axis of the legend 142 well beyond Figure 4 123, 125 to provide magnetic isolation between other adjacent interconnect members contained in the signal paths 123, 125. For example, the EM shield structure 138 may be sized to extend Figure 3131. The EM shielding structure 138 may extend all or substantially all of the primary magnetic interference region 110 in the EM shielding circuit 60. Alternatively, the EM shielding structure 138 may not extend all of the magnetic interface region 110; and the EM shielding structure 138 may instead be given a reduced size, wherein multiple instances of the structure 138 are incorporated into the EM shielding circuit 60. Regardless, the EM shielding structure 138 may be bonded to the substrate 130 in a variety of ways, wherein the structure 138 is oriented so that the opposing major faces of the structure 138 form substantially right angles with the substrate front side 131. For example, the EM shielding structure 138 may be formed solely of the substrate 130 and brazed or bonded to the substrate 130 using a die attach material, epoxy, sintered metal material, or other adhesive. Furthermore, in certain embodiments, a lower portion or edge of the structure 138 may be matingly received within a shallow trench 139 formed in the front side 131 of the substrate 130 for added support.

[0109] Continue to view Figure 4 , the EM shielding structure 138 has a peak height H MS , as measured along an axis orthogonal to the front side 131 of the substrate 130 and parallel to the Z axis of the coordinate diagram 142; a maximum length L MS , as measured along an axis parallel to the substrate 130 and to the Y axis of the coordinate graph 142; and an average thickness T MS , as measured along an axis parallel to the substrate 130 and to the X-axis of the legend 142. As noted above, H MS , L MS and T MS will vary among embodiments and need not remain constant across the entirety of the EM shielding structure 138. Typically, however, H MS will generally be equal to or greater than the peak height of the bond wire arrays 120, 122, which are as shown in FIG. Figure 4 The double-headed arrow "H WB ” and is also measured along an axis orthogonal to the substrate front side 131. Similarly, L MS will generally be equal to or greater than the maximum length of one or both of the bond wire arrays 120, 122, such as Figure 4 The double-headed arrow "L WB ” and measured along an axis parallel to the Y axis of the coordinate legend 142. Sizing the EM shielding structure 138 in this manner can better adjust the range of the magnetic field induced when the current carrying the signal passes through the arrays 120, 122 to maximize the effect of the structure 138.

[0110] The thickness of the EM shielding structure 138 may be constant, or may otherwise vary to provide enhanced magnetic shielding in areas of higher flux line concentration. In one embodiment, the EM shielding structure 138 has an average thickness (T ) in the range of 1 to 100 millimeters (mm), and more preferably 5 to 50 mm. MS ). In such embodiments or in other embodiments, the magnetic shielding layer 141 may constitute or include at least half of the thickness of the EM shielding structure 138, such that the thickness of the layer 141 is equal to or greater than the thickness of the electric shielding layer 140 and may be at least twice the thickness of the layer 140. As a more specific example, and without loss of generality, the magnetic shielding layer 141 may constitute or include about 50% to about 90% of the total thickness of the EM shielding structure 138 (again, as measured along an axis orthogonal to the major face of the shielding structure 138), with the electric shielding layer 140 constituting the remainder of the thickness of the shielding structure 138. In still other embodiments, T MS The aforementioned ranges may be greater or less than, and / or the relative thicknesses of layers 140, 141 may vary relative to the examples set forth above.

[0111] Figure 5 1 and 2. The simulated improvements in gain, cross-coupling, and isolation achieved by the EM shielded microelectronic assembly 118 are graphically depicted. In this simulation, the magnetic shielding layer 141 ( Figure 4 ) is made of Mu metal and has a constant thickness of 10 mm, while the electrical shielding layer 140 is made of Cu sheet and has approximately the same thickness. In addition, the EM shielded microelectronic assembly 118 is simulated as an RF circuit structure (e.g., a 2-way RF power amplifier) ​​that can operate in the frequency range of 3.2 to 3.8 GHz. The performance of the EM shielded microelectronic assembly 118 (as determined by Figure 5 ) is compared to a similar microelectronic assembly with an electrical (Cu) shielding structure but no magnetically permeable shielding layer (represented by the second trace pattern) and a similar circuit without any shielding structure (represented by the third trace pattern). Figure 5 As can be seen from the middle row of the graph presented in FIG. 1 , in the case of the EM shielding microelectronic assembly 118, due to the provision of the EM shielding structure 138 ( Figure 4 ), the magnetic cross-coupling between the two analog signal paths is greatly reduced during assembly operation. Correspondingly, as indicated in the lower row of the graph, the magnetic isolation between the different signal paths is significantly improved; for example, the provision of the EM shielding structure 138 shows an isolation improvement within 10 decibels (dB) compared to a microelectronic assembly containing an electrical (e.g., Cu) shield and within 20 dB compared to a microelectronic assembly without any shield. Finally, as indicated in the lower row of the graph, the magnetic isolation between the different signal paths is significantly improved; for example, the provision of the EM shielding structure 138 shows an isolation improvement within 10 decibels (dB) compared to a microelectronic assembly containing an electrical (e.g., Cu) shield and within 20 dB compared to a microelectronic assembly without any shield. Figure 5As indicated in the upper row of the graph in FIG. , the EM shielding structure 138 ( Figure 4 ) may provide a small (if non-negligible) loss in gain.

[0112] As described above, the EM shielding structure 138 is Figure 4 1 has a relatively simple two-layer construction. Advantageously, when manufacturing structure 138, such a construction can reduce the cost and complexity of manufacturing. EM shielding structure 138 can be manufactured in a variety of different ways. For example, in one method, magnetic shielding layer 141 can be cut (e.g., via laser cutting, water jetting, stamping, sawing, or the like) from a larger sheet of magnetically permeable material, and the magnetic shielding layer 141 is singulated into multiple shielding structures. Examples of such materials are described above in conjunction with Figure 2 1 and 14. The EM shielding structure 52 shown in FIG. 1 is discussed in conjunction with the EM shielding structure 52 shown in FIG. 1 and includes Mu metal, Fe-based alloys (e.g., Permalloy), electrical steel, and various other alloys with relatively high magnetic permeability. The electrical shielding layer 140 may be formed on the magnetic shielding layer 141 by, for example, plating or electrodepositing a conductive alloy on the magnetically conductive thin sheet before or after singulation of the magnetically conductive thin sheet. Alternatively, the electrical shielding layer 140 may likewise be cut from a larger sheet or panel of conductive material and then bonded to the magnetic shielding layer 141 using, for example, a die attach material, a sintered metal material, a metal-filled epoxy, or the like. As yet another possibility, the electrical shielding layer 140 may be first manufactured and then the electrical shielding layer 140 may be used as a substrate to deposit the magnetic shielding layer 141 onto the substrate, for example, by plating a magnetically conductive alloy onto a selected surface of the magnetic shielding layer 141, by sputtering or depositing a magnetically conductive alloy onto a selected surface of the magnetic shielding layer 141 in another manner. In such embodiments, the electrical shielding layer 140 may also be considered a "substrate layer" or "shielding substrate." In still other embodiments, the layers 140, 141 may not be directly joined, but instead may be in close contact or placed in close proximity. While the relatively simple construction of the EM shielding structure 138 may reduce costs, other advantages may be obtained by manufacturing the structure 138 with a more complex construction. For example, in further embodiments, the EM shielding structure may include one or more patterned or shaped layers of magnetically permeable and / or electrically conductive material, as described below with reference to FIG. Figures 6 to 10 Combined with what has been discussed.

[0113] Figure 6 and 7 1 is an isometric view of an EM shielding microelectronic assembly 144 including an EM shielding structure 146 as shown in accordance with another exemplary embodiment of the present disclosure. The EM shielding microelectronic assembly 144 is similar to the EM shielding microelectronic assembly 118, wherein the assemblies 118, 144 share several common structural elements. Thus, where appropriate, the previously described EM shielding microelectronic assembly 144 is similar to the EM shielding microelectronic assembly 118. Figure 4 The reference numerals used in conjunction with the introduction have been carried forward to Figure 6 and 7 , and the foregoing descriptions of the signal paths 123, 125, the bond wire arrays 120, 122, and the assembly substrate 130 apply identically. As was the case previously, in the illustrated example, the EM shielding structure 146 has a generally rectangular, wall-like or plate-like form factor and extends upward from the front side of the assembly substrate 130 between the bond wire arrays 120, 122. In other words, the EM shielding structure 146 forms a right angle with the substrate 130 and physically divides or separates the bond wire arrays 120, 122 as viewed along an axis orthogonal to either of the opposing major faces of the structure 146. Thus, again, the bond wire arrays 120, 122 are located on opposite sides of the EM shielding structure 146. In further embodiments, the EM shielding structure 146 may have a more complex shape, such as a curvilinear planar geometry or a planar geometry defined by a plurality of intersecting walls.

[0114] Compared to Figure 4 1, the EM shielding structure 138 in the microelectronic assembly 118 shown in FIG. 1, the EM shielding structure 146 in the microelectronic assembly 144 has a more complex multi-layer structure. Specifically, in Figures 6 to 7 In the example shown in FIG. 1 , the EM shielding structure 146 includes a dielectric substrate layer or shielding substrate 148 having opposing major surfaces 150, 151 that face the bonding wire arrays 122, 120, respectively. Figure 6 As most clearly shown in FIG. 1 , a first patterned magnetically permeable material layer 152 (hereinafter, “patterned magnetic shielding layer 152”) is formed on the major surface 150 of the substrate layer 148. Similarly, and as Figure 7 , a patterned conductive material layer 154 (hereinafter, "patterned electrical shielding layer 154") may be formed on a substrate surface 151 opposite the patterned magnetic shielding layer 152. The layers 152, 154 are thus positioned adjacent to each other, but separated by the substrate layer 148, and may also be referred to as being indirectly joined. In the example shown, the EM shielding structure 138 is thus similar to or equivalent to a double-sided printed circuit board (PCB) or a wiring board. In further embodiments, the shielding structure 138 may include a greater or lesser number of patterned or unpatterned (continuous) layers.

[0115] The substrate layer 148 may be made of a metallic material, a dielectric material of the type commonly used in PCB manufacturing (e.g., polytetrafluoroethylene or polyimide), a ceramic, or another material. The patterned magnetic shielding layer 152 may be deposited on the main surface 150 of the substrate layer 148 in different ways, wherein the selected deposition process depends on the composition of the substrate layer 148, the composition of the shielding layer 152, the desired thickness of the shielding layer 152, and other such factors. For example, the patterned magnetic shielding layer 152 may be electroplated onto the substrate surface 150 in a magnetically conductive (e.g., Fe-rich) plating manner. In other embodiments, the patterned magnetic shielding layer 152 may be applied to the surface 150 of the substrate layer 148 using a film transfer process, in the form of a B-stage epoxy resin, or via a silk screen application. On the latter aspect, a wet material (e.g., a paste, a coating, or a slurry) comprising magnetically conductive particles dispersed in a liquid carrier or solvent (e.g., water or a high molecular weight alcohol) may be prepared or obtained. The wet material may also contain other components, such as organic additives (e.g., acrylics) added for strengthening purposes. After the wet material is applied to the substrate surface 150 using a suitable process (e.g., a silk screen process or another deposition process capable of depositing a flowable material in the desired pattern, such as fine needle dispensing), the wet material may then be thermally treated (e.g., dried and possibly baked) to remove some or all of the organic portion from the wet material, thereby producing a patterned magnetic shielding layer 152.

[0116] Continue to view Figures 6 to 7 , and if Figure 7 As most clearly shown in FIG. 1 , the patterned electric shield layer 154 can be formed on the substrate surface 151 in combination with the patterned magnetic shield layer 152 using the various deposition processes described above. In other embodiments, the electric shield layer 154 can be patterned using well-known metal deposition and photolithography techniques, such as those commonly used to make metal traces on circuit boards. In addition, if desired, the patterned electric shield layer 154 can be electrically coupled to the substrate surface 151 by, for example, electrically coupling the patterned electric shield layer 154 to the substrate surface 151. Figure 7 The electrical shielding layer 154 is electrically grounded to a ground trace, via, coin, or other electrically grounded interconnect member indicated by reference numeral 156 in the embodiment. As described above, grounding of layer 154 can help reduce eddy current losses and provide other performance benefits. The composition and thickness of patterned electrical shielding layer 154 will vary among embodiments; however, in one embodiment, electrical shielding layer 154 is at least primarily composed of Cu, Al, or Au by weight and has a thickness between 0.01 and 10 mm. More generally, electrical shielding layer 154 will typically be composed of less than 10 mm thick magnetic shielding layer 152 ( Figure 6) is composed of a material having a higher electrical conductivity but a lower magnetic permeability than the material that constitutes the magnetic shielding layer 152. For example, in some embodiments and in a manner equivalent to that previously described, if the electrical conductivity of the electric shielding layer 154 is not at least twice the electrical conductivity of the material that constitutes the magnetic shielding layer 152, then the electric shielding layer 154 may be composed of a material having an electrical conductivity that is at least 50% higher than the electrical conductivity of the material that constitutes the magnetic shielding layer 152; and if the magnetic permeability of the magnetic shielding layer 152 is not at least twice the magnetic permeability of the material that constitutes the electric shielding layer 154, then the magnetic shielding layer 152 may be composed of a material having a magnetic permeability that is at least 50% higher than the magnetic permeability of the material that constitutes the electric shielding layer 154.

[0117] Several benefits are achieved by forming the EM shielding structure 146 including patterned shielding layers 150, 152 in the manner described above, rather than by forming the structure 146 containing an unpatterned continuous layer. First, some degree of cost reduction can be achieved through the reduced volume of the shielding layers 150, 152, particularly when more expensive materials are used to make one or both of the shielding layers 150, 152. Second, by minimizing the shielding material surface area, problems such as RF mismatch, reduced bond line Q (which can cause increased eddy current losses in the shielding structure), and memory effects (hysteresis) can be significantly reduced, if not substantially avoided. Nevertheless, in other embodiments, one or both of the layers 150, 152 can be provided as an unpatterned layer or sheet. For example, in an alternative embodiment, the electrical shielding layer 154 can be formed as a continuous sheet or wall, while the magnetic shielding layer 152 can be directly bonded to the layer 154 as a shield with the shielding material surface area. Figure 6 A similar or identical patterned layer as shown in .

[0118] When the magnetic shielding layer 152 is provided as a patterned layer, the magnetic shielding layer 152 is effectively spatially distributed in those areas where the flux concentration is the highest. As viewed along an axis orthogonal to the substrate surfaces 151, 152, a specific pattern in which the magnetic shielding layer 152 is deposited can be selected to substantially simulate or mirror the arched bond line profile of the bonding wire 124, the bonding wire 132, or both the bonding wires 124, 132. In other words, the bonding wires 124, 132 can be bent into a curved shape as shown, and the magnetic shielding layer 152 (and possibly the electrical shielding layer 154) is patterned into a top view geometry having a curved shape corresponding to or close to the bonding wires 124, 132; as it appears in this article, the term "planar geometry" refers to the geometry of the layer 152 (or layer 154, as the case may be) viewed along an axis orthogonal to the substrate surfaces 151, 152. Additionally or alternatively, data may be collected, whether by computer simulation or using physical testing equipment, to plot the surface of the substrate 130 that is normal to the front side and not aligned with the major surface 150 ( Figure 6) is coplanar, then the flux line concentration in a plane that is parallel to the major surface 150 of the substrate layer 148 may be. An example of such a computer simulation 158 is shown in Figure 8 , where the concentration of flux lines within the plane 160, indicated by the changing color (represented by the changing degree of shading in the diagram), changes. Such simulation data 158 can therefore be used to define the size and shape of the patterned magnetic shielding layer 152 by judiciously distributing the magnetic shielding material in those areas of the highest flux line concentration, and therefore most susceptible to magnetic cross-coupling. In addition, if desired, the thickness of the magnetic shielding layer 152 can be changed based on such plotted flux concentration data; for example, such that the local thickness of the magnetic shielding layer 152 is increased in areas of peak flux line concentration, such as Figure 6 Roughly shown in the figure.

[0119] In the manner described above, the provision of the EM shielding structure 146 can improve the magnetic isolation rate during operation of the microelectronic assembly 144; for example, test data indicates that isolation rates approaching or exceeding 15 dB can be achieved in at least some embodiments of the assembly 144. At the same time, the patterned and possibly grounded electric shielding layer 154 can provide performance benefits, such as reduced eddy current losses, as discussed above. The EM shielding structure 146 can still be manufactured using a batch manufacturing process as desired; for example, the structure 146 can be produced in parallel with multiple similar structures by forming patterned layers on opposite sides of a larger panel, the larger panel containing the dielectric substrate layer 148 and the larger panel is then singulated into smaller pieces. In other embodiments, the dielectric substrate layer 148 can be replaced with a non-patterned or continuous electric shielding layer (where the patterned magnetic shielding layer 152 is formed on one or both sides of the electric shielding layer); or alternatively, the dielectric substrate layer 148 can be replaced with a non-patterned magnetic shielding layer (where the electric shielding layer 154 is formed on one or both sides of the magnetic shielding layer).

[0120] Although in Figures 6 to 8 The example includes a patterned magnetic shielding layer 152, but the EM shielding structure 146 still has the same Figures 4 to 5 A relatively simple wall-like or fin-like form factor similar to the EM shielding structure 138 described in conjunction with the present invention may be provided. Additional embodiments of the EM shielding structure may take other forms, however, provided that at least a portion of the shielding structure is physically positioned between adjacent interconnecting members, devices, or other circuit elements included in the separated signal paths and is at least partially composed of a magnetically permeable material. For example, in an alternative embodiment, the EM shielding structure may be produced as a wire fence composed at least partially of a magnetically permeable material, as described below with reference to Fig. 9 and 10 Combined with the description.

[0121] Continue to refer to Fig. 9, an EM shielding microelectronic assembly 162 is shown according to another exemplary embodiment of the present disclosure. Likewise, where appropriate, Figure 4 , 6 The same reference numerals as 7 have been used to Fig. 9 . In this example, the EM shielding microelectronic assembly 162 includes an EM shielding structure 164 that is formed as an arched wire that mimics or follows the bond wire profile of the bond wires 124, 132. In other words, the EM shielding structure 164 is imparted with a curvilinear shape that substantially matches, follows, or corresponds to the curvilinear shape of the bond wires 124, 132. In certain embodiments, the EM shielding structure 164 may be formed entirely of a magnetically permeable material and bonded to a bonding pad 166. In this case, the EM shielding structure 164 may be formed using a wire bonding tool but replacing a wire feed composed of a magnetically permeable metal or alloy (e.g., Mu metal) with a conductive material (e.g., Au, Ag, or Cu) used in conventional bond wire formation. Alternatively, in such embodiments, the EM shielding structure 164 may be produced using a three-dimensional printing process. In yet other embodiments, the EM shielding structure 164 may contain a conductive wire core with a magnetically permeable coating applied over the conductive wire core. The latter possibility is indicated in Fig.10 middle, Fig.10 is a cross section through the EM shielding structure 164 showing a conductive (e.g., Cu, Au, or Ag) wire core 168 surrounded by a magnetically conductive (e.g., Mu metal) wire coating 170. Fig.10 As indicated by the dashed lines in , in embodiments, a coating 172 may be disposed around the wire core 168 (eg, Cu wire coated with stainless steel or nickel may be utilized), in which case the magnetic wire coating 170 may be bonded to the coating 172 .

[0122] The EM shielding structure 164 includes a conductive wire core 168 ( Fig.10 ) embodiment, the wire core 168 can be connected to the pad 166 and the interconnecting member 174 ( Fig. 9) is electrically coupled to ground, the bonding pad 166 and the interconnect member 174 such as a metal trace, via, metal plug, or the like formed in the substrate 130. In addition, grounding the wire core 168 in this manner can help reduce eddy current losses within the EM shielding structure 164 during operation of the microelectronic assembly 162. The magnetic wire coating 170 can be applied to the wire core 168 before or after bonding to the bonding pad 166. For example, in an embodiment, a wet coating technique is used to apply a precursor material (e.g., a paste or paint) containing magnetically conductive particles to the wire core 168; and a curing process (e.g., a heat treatment) is then performed to convert the precursor material into the wire coating 170 by, for example, removing some or all of the organic material (e.g., a liquid carrier and any organic binder) from the precursor material. In other embodiments, different coating techniques may be utilized; or, as described above, the EM shielding structure 164 may be composed entirely of magnetically conductive materials.

[0123] Then proceed to Fig.11 , shows an EM shielding microelectronic assembly 176 including an EM shielding structure 178 as depicted according to yet another exemplary embodiment of the present disclosure. Again, the EM shielding microelectronic assembly 176 is similar to the above-described EM shielding microelectronic assembly 176. Figures 4 to 10 In conjunction with the described microelectronic assemblies 118, 144, 162, reference numerals are used where appropriate. However, in contrast to the EM shielding microelectronic assemblies 118, 144, 162 described above, the EM shielding microelectronic assembly 176 additionally includes two microelectronic devices 180 located on opposite sides of a body or shielding wall 182 of an EM shielding structure 178, the EM shielding structure 178 being oriented to extend substantially orthogonally to the upper major face or front side of the substrate 130, as previously described. In this particular example, the microelectronic devices 180 are depicted as integrated capacitor structures. Thus, the microelectronic devices 180 each include a dielectric layer 184 separating two conductive layers 186 formed in the substrate 130 (shown in phantom to better illustrate the devices 180) at a location below the shielding structure 178 as viewed along an axis orthogonal to the front side of the substrate 130. In other embodiments, the microelectronic device 180 may take other forms, such as a chip capacitor or other passive SMD mounted to the upper surface of the substrate 130 .

[0124] The microelectronic device 180 is at least partially nested or positioned between the bonding wire arrays 120, 122. In other words, the bonding wire arrays 120, 122 extend over the device 180 in a bridge-like manner. Alternatively, some or all of the bonding wires in the bonding wire arrays 120, 122 may physically and electrically contact the top surface of the microelectronic device 180 along the length of the bonding wires to provide an electrical connection to the microelectronic device 180 (specifically when the wing-shaped portions 188 described below are not included in the assembly 176). Such an arrangement enables a highly dense circuit structure, but in addition, if adequate precautions are not provided, there is a chance of undesirable EM cross-coupling occurring between the device 180 and the bonding wire arrays 120, 122. Therefore, in Fig.11 In the example of EM shield structure 178, an EM shield structure 178 is fabricated that additionally includes two lateral extensions or shield wings 188 that extend in a direction above the microelectronic device 180 opposite to the major face of the body 182 of the EM shield structure 178. The shield wings 188 thus at least partially cover or shield the device 180 as viewed along an axis orthogonal to the upper surface of the substrate 130. The shield wings 188 may or may not be directly bonded to the microelectronic device 180; and along with the body 182 of the EM shield structure 178, the wings 188 may be formed of a magnetically permeable material of the type previously described to reduce magnetic cross coupling between the device 180 and the bond wire arrays 120, 122 during operation of the EM shield microelectronic assembly 176. In yet further embodiments, the wing 188 may be replaced by a discrete sheet or block of material that is bonded (e.g., with epoxy or die attach material) to the upper surface of the microelectronic device 180. As yet another possibility, in an alternative embodiment of the EM shielding microelectronic assembly 176, the shielding wing 188 may be replaced by a deposited layer of magnetically permeable material (e.g., sputter deposited Mu metal or Permalloy) applied directly onto the upper surface of the device 180.

[0125] Finally, if desired, an EM shielding structure 178 may be fabricated that includes one or more electrical shielding layers 190 that may contact and / or bond to one or more magnetic shielding layers 191 that are additionally included in the shielding structure 178. For example, Fig.11, the electric shielding layer 190 may be provided as a continuous (non-patterned) layer or body disposed between two magnetic shielding layers 191 that face the opposing wire bond arrays 124. To this end, in certain embodiments, the electric shielding layer 190 may be a core layer to which the magnetic shielding layer 191 is bonded as a mirror image opposite side using, for example, epoxy or other bonding materials. As previously indicated, the electric shielding layer 190 may be composed of a material having a magnetic permeability that is less than the magnetic permeability of a portion of the EM shielding structure 178 and an electrical conductivity that is greater than the electrical conductivity of a portion of the EM shielding structure 178 that is made of a magnetically permeable material (i.e., the shielding layer 191). Furthermore, in at least some embodiments, if the electrical conductivity of the electric shielding layer 190 is not at least twice the electrical conductivity of the material constituting the magnetic shielding layer 191, the electric shielding layer 190 may be composed of a material having an electrical conductivity at least 50% higher than the electrical conductivity of the material constituting the magnetic shielding layer 191; and if the magnetic permeability of the magnetic shielding layer 191 is not at least twice the magnetic permeability of the material constituting the electric shielding layer 190, the magnetic shielding layer 191 may be composed of a material having a magnetic permeability at least 50% higher than the magnetic permeability of the material constituting the electric shielding layer 190. When the electric shielding layer 190 is provided, the electric shielding layer 190 may be electrically grounded or may be kept electrically floating. In alternative embodiments, the EM shielding structure 178 may lack such a conductive core layer; or, as desired, the EM shielding structure 178 may be manufactured to include additional regions or portions formed of conductive materials to meet specific applications or uses.

[0126] Additional Examples of Microelectronic Modules and Systems Incorporating EM Shielding Structures

[0127] While the above mainly relates to exemplary microelectronic packages, such as Figure 3 62 shown in conjunction with the description, it is emphasized that the embodiments of the EM shielding structures described herein are not limited thereto. Rather, embodiments of the EM shielding structures may be integrated into a variety of different types of microelectronic assemblies susceptible to EM cross-coupling, including, but not limited to, microelectronic modules and systems. As a more specific example, embodiments of the presently disclosed EM shielding structures may be advantageously integrated into modules and systems containing RF circuits and / or having a relatively compact form factor, e.g., to reduce EM cross-coupling between closely spaced active devices. To further emphasize the versatility of the EM shielding structures described above, a microelectronic assembly 200 in the form of an exemplary massive MIMO transceiver module is additionally presented in Fig.12, as seen from a top-down or top-down perspective. In this example, the microelectronic assembly 200 includes two EM wall shield structures 202, 204 that are joined to an assembly substrate 206 at strategically selected locations to reduce EM cross-coupling between devices, networks, or modules carrying different electrical signals. In addition to the EM shield structures 202, 204 and the assembly substrate 206, the microelectronic assembly 200 further includes a plurality of terminals 208 (e.g., female coaxial connectors) that are electrically interconnected with various other devices (e.g., SMDs), an RF PA package device 210, and a plurality of other microelectronic package devices 212. The package devices 210, 212 include transmitter path circuits (generally composed of) in the assembly 200. Fig.12 214 in the figure) and in the receiver path circuit (outlined by box 216).

[0128] The EM shielding structure may be disposed at any number of locations within the assembly 200; for example, one or more EM shielding structures may be effectively integrated in the RF PA package device 210 between different RF subnetworks; for example, between peaking and carrier amplification paths when the device 210 includes a Doherty PA. The EM shielding structure 202 may also be disposed between the receiver path circuit 214 and the transmitter path circuit 216, such as Fig.12 . In general, shielding members may also be disposed between analog (RF) networks and digital networks contained in the assembly 200, and / or may otherwise be disposed around the outer perimeter of the circuitry of the assembly 200. In this regard, the EM shielding structure 204 may include an outer peripheral wall or cage portion 218 extending around the perimeter of the core circuit elements contained in the assembly 200. The peripheral wall 218 may form a closed polygonal shape (e.g., a rectangular shape) as viewed from a top-down or top-down perspective, i.e., along the Z-axis identified by the coordinate legend 222. In addition, the EM shielding structure 204 may include a partition wall or internal divider 220 that physically separates portions of the receiver network and the transmitter network included in the assembly 200. The shielding structures 202, 204 may be provided with the above-described Figures 2 to 4 , Figure 6 , Figure 7 and Fig.11 Thus, each can produce an EM shielding structure 202, 204 including an electrical shielding portion or layer engaged with (or in contact with or in close proximity to) a magnetic shielding portion or layer, as previously described and as described above. Fig.12222. The EM shielding structures 202, 204 are effectively endowed with an average or peak height (as measured along the Z-axis of legend 222) that is equal to or greater than the height of one or all of the packages 210, 112; however, the respective heights (and other dimensions) of the shielding structures 202, 204 may vary in other embodiments. In this manner, the provision of the EM shielding structures 202, 204 may thereby reduce, if not eliminate, EM cross-coupling during operation of the assembly 200 to provide the enhancements in assembly performance described above.

[0129] in conclusion

[0130] Thus, examples of EM shielded microelectronic assemblies have been provided that reduce EM cross-coupling between different signal paths contained in the microelectronic assembly to enhance performance even when the assembly operates at higher (e.g., RF) frequencies and / or relatively high power levels and is given a relatively compact form factor. While described above primarily in the context of high frequency RF applications, the EM shielded microelectronic assembly may be used in a variety of different applications where EM cross-coupling between different signal lines is generally problematic, whether the signal paths carry digital signals (e.g., as in the case of clock lines), analog signals, or a combination thereof. As further described above, the EM shielded microelectronic assembly may be integrated into a variety of different types of microelectronic packages, modules, and assemblies without restriction. The EM shielding structures described above may achieve significant improvements in isolation ratios, which may approach or exceed 20 dB in at least some cases, compared to microelectronic assemblies incorporating conventional electrical shielding structures. The embodiments of the invention described above are therefore well suited for integration into highly linear and efficient (e.g., LDMOS, GaN, or other) RF power amplifiers. Furthermore, due to the proximity of active devices in integrated products, embodiments of the present disclosure are well suited for use in such integrated products, such as RF amplifiers and / or transceiver modules. In yet further embodiments, the EM shielding microelectronic assembly may be incorporated into various other types of microelectronic devices in which enhanced EM shielding is desired.

[0131] In an embodiment, the EM shielding microelectronic assembly (e.g., package, module, or system) described above includes a first signal path and a second signal path, wherein the first signal path and the second signal path carry different or unique electrical signals during operation of the microelectronic assembly. An EM shielding structure is positioned between the first signal path and the second signal path. The EM shielding structure further includes a magnetic shielding portion that is adjacent to (e.g., in contact with and / or directly or indirectly joined to and / or does not contain other intervening structures) the electrical shielding portion. The magnetic shielding portion has a first magnetic permeability and a first electrical conductivity, while the electrical shielding portion has a second magnetic permeability that is less than the first magnetic permeability and has a second electrical conductivity that is greater than the first electrical conductivity. In addition, in certain embodiments, the first magnetic permeability (the magnetic permeability of the magnetic shielding portion or layer) may be at least 10% higher than the second magnetic permeability, preferably at least 50% higher, and more preferably at least twice the second magnetic permeability. Additionally or alternatively, the second electrical conductivity (the electrical conductivity of the electrical shielding portion or layer) may be at least 10% higher than the first electrical conductivity, preferably at least 50% higher, and more preferably at least twice the first electrical conductivity. In this way, the EM shielding structure reduces EM cross-coupling between the first signal path and the second signal path during operation of the EM shielded microelectronic assembly.

[0132] In another embodiment, an EM shielding microelectronic assembly includes a first signal path and a second signal path that carry different electrical signals during operation of the electromagnetic shielding microelectronic assembly. The microelectronic assembly further includes a first interconnect member (e.g., a first metal trace or bonding wire), a second interconnect member (e.g., a second metal trace or bonding wire), and a substrate having a front side, the first signal path extending through the first interconnect member, the second signal path extending through the second interconnect member, the first interconnect member and the second interconnect member being connected to the front side such as by bonding to a bonding pad present on the front side of the substrate or through a microelectronic device (e.g., a semiconductor die) mounted to the front side. The EM shielding structure contains: (i) a shielding substrate that protrudes from the front side of the substrate at a position between the first interconnect member and the second interconnect member; and (ii) a patterned magnetic shielding layer that contacts (e.g., directly bonds) with a first main surface of the shielding substrate. The patterned magnetic shielding layer is composed of a magnetically permeable material to reduce EM cross coupling between the first signal path and the second signal path during operation of the electromagnetic shielding microelectronic assembly. In certain embodiments, the electromagnetic shielding microelectronic assembly may further include an RF PA circuit, in which case the first signal path and the second signal path may be in the form of a first (e.g., peaking and carrier) amplifier path and a second (e.g., peaking and carrier) amplifier path, respectively, included in the RFPA circuit.

[0133] In some cases, the EM shielding microelectronic assembly described in the preceding paragraph may contain a patterned electrical shielding layer that contacts (e.g., is bonded) with a second relative main surface of the shielding substrate that is opposite to the patterned magnetic shielding layer. In such cases, the shielding substrate may be composed of a dielectric material, and the patterned electrical shielding layer is electrically grounded; for example, an electrical conductor (such as a trace) may be connected to the electrical shielding layer to connect the shielding layer to ground. In other cases, the magnetically permeable material may have a first magnetic permeability and a first electrical conductivity, and the shielding substrate is composed of a material having a second magnetic permeability less than the first magnetic permeability and a second electrical conductivity greater than the first electrical conductivity. In yet other cases, the first interconnect member may be in the form of a bonding wire having an arched or curved bonding wire profile, and the patterned magnetic shielding layer is patterned to have an arched planar geometry that substantially corresponds to or simulates the arched bonding wire profile.

[0134] In yet another embodiment, an EM shielding microelectronic assembly includes: a first signal path and a second signal path; a first bonding wire, the first signal path extends through the first bonding wire; a second bonding wire, the second signal path extends through the second bonding wire; and an EM shielding structure, the EM shielding structure is positioned between the first bonding wire and the second bonding wire. The EM shielding structure is at least partially composed of a magnetically permeable material, thereby reducing magnetic cross-coupling between the first bonding wire and the second bonding wire during operation of the electromagnetic shielding microelectronic assembly. The magnetically permeable material may exist as, for example, a continuous layer, a patterned layer, or a magnetically permeable coating. As a more specific example, in some embodiments, the EM shielding structure may include a conductive wire core and a magnetically permeable coating formed around the wire core.

[0135] Embodiments of methods for manufacturing EM shielding microelectronic assemblies and EM shielding structures have also been provided. For example, in an embodiment, a method may include a step or process of providing a microelectronic assembly including a first signal path and a second signal path, wherein the first signal path and the second signal path carry different electrical signals during operation of the microelectronic assembly. The EM structure may be disposed between the first signal path and the second signal path. In certain embodiments, an EM structure may be formed including: (i) a magnetic shielding portion having a first magnetic permeability and a first electrical conductivity; and (ii) an electrical shielding portion bonded to the magnetic shielding portion, the electrical shielding portion having a second magnetic permeability less than the first magnetic permeability and having a second electrical conductivity greater than the first electrical conductivity. In other embodiments, the EM structure may include a shielding substrate to which a patterned magnetic shielding layer is bonded. The patterned magnetic shielding layer may be imparted with a curved or arched planar geometry that may substantially follow or correspond to the shape of a bonding line that is adjacent to the EM structure and through which the first signal path extends. Additionally or alternatively, the method may include mapping magnetic flux concentrations that occur during operation of the microelectronic assembly at locations of the patterned magnetic shielding layer (e.g., via Figure 8 The steps of the computer simulation shown in ) are performed, and the magnetic flux concentration causes the patterned magnetic shielding layer to have an increased thickness in the area of ​​higher magnetic flux concentration. Finally, as another possibility, in some cases, an EM structure can be produced that includes a patterned electric shielding layer opposite to the patterned magnetic shielding layer bonded to the shielding substrate.

[0136] Although at least one exemplary embodiment has been presented in the foregoing detailed description, it should be understood that there are a large number of variations. It should also be understood that one or more exemplary embodiments are merely examples and are not intended to limit the scope, applicability or configuration of the present invention in any way. In fact, the foregoing detailed description will provide a convenient guide for implementing the exemplary embodiments of the present invention to those skilled in the art. It should be understood that various changes may be made to the functions and arrangements of the elements described in the exemplary embodiments without departing from the scope of the present invention as set forth in the appended claims.

Claims

1. An electromagnetic shielding microelectronic assembly, characterized in that: include: a first signal path and a second signal path, the first signal path and the second signal path carrying different electrical signals during operation of the microelectronic assembly; and An electromagnetic EM shielding structure, wherein the EM shielding structure is positioned between the first signal path and the second signal path, and the EM shielding structure comprises: a magnetic shield portion having a first magnetic permeability and a first electrical conductivity; and an electric shielding portion, the electric shielding portion being adjacent to the magnetic shielding portion, the electric shielding portion having a second magnetic permeability less than the first magnetic permeability and having a second electrical conductivity greater than the first electrical conductivity, wherein the EM shielding structure further comprises a dielectric substrate layer, the dielectric substrate layer having a first main surface and a second main surface opposite to the first main surface; and wherein the magnetic shielding portion includes a magnetic shielding layer in contact with the first main surface, wherein the electric shielding portion comprises an electric shielding layer in contact with the second main surface of the dielectric substrate layer, wherein the electromagnetic shielding microelectronic assembly further comprises an assembly substrate having a front side, the EM shielding structure protruding from the front side, The electromagnetic shielding microelectronic assembly further comprises: a first interconnect member through which the first signal path extends, the first interconnect member being bonded to the substrate and located on a first side of the EM shield structure; and a second interconnect member through which the second signal path extends, the second interconnect member being bonded to the substrate and located on a second opposite side of the EM shield structure, And wherein the first interconnect member includes a bonding wire bent into a curved shape, and wherein at least one of the magnetic shielding layer and the electric shielding layer is patterned to have a planar geometry corresponding to the curved shape of the bonding wire.

2. The electromagnetic shielding microelectronic assembly according to claim 1, characterized in that: Further included is a ground conductor connected to the electrical shield portion and coupling the electrical shield portion to an electrical ground.

3. The electromagnetic shielding microelectronic assembly according to claim 1, characterized in that: The magnetic shield portion includes a coating composed of a magnetically permeable material and formed over an outer surface of the electrical shield portion.

4. The electromagnetic shielding microelectronic assembly according to claim 1, characterized in that: Further including: a substrate having a front side; a first bond wire coupled to the front side and through which the first signal path extends; and A microelectronic device over which the first bond wire extends, the microelectronic device being at least partially covered by the EM shielding structure taken along an axis orthogonal to the front side.

5. The electromagnetic shielding microelectronic assembly according to claim 1, characterized in that: Further comprising a radio frequency power amplifier circuit; The first signal path and the second signal path include a first amplifier path and a second amplifier path, respectively, and the first amplifier path and the second amplifier path are included in a radio frequency power amplification circuit.

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