System for electromagnetic shielding

Abstract

Systems for electromagnetic shielding, in particular for semiconductor packages and / or printed circuit boards, are provided. The system includes: a substrate; an optical device attached to the substrate; an RF cap attached to the substrate, where the RF cap includes a first aperture aligned with an optical axis of the optical device; a cured deposition layer including at least a first portion of the deposition layer and a second portion of the deposition layer, where the first portion of the deposition layer is disposed across the first aperture of the RF mask and includes a second aperture narrower than the first aperture and aligned with the optical axis, where the second portion of the deposition layer is disposed on the RF mask and the first terminal of the substrate, and wherein the first portion of the deposited layer is not connected to the second portion of the deposited layer; and wherein the deposition layer electrically couples the RF cap to the first terminal of the substrate to provide a first electromagnetic shield for at least the optical device.

Description

Technical Field

[0001] Example embodiments of the present disclosure generally relate to electromagnetic shielding for semiconductor packages and / or printed circuit boards. Background Art

[0002] Components on a semiconductor package and / or a printed circuit board (PCB) may be exposed to electromagnetic interference (EMI), which may cause the components on the semiconductor package and / or the PCB to malfunction or operate with reduced efficiency.

[0003] The inventors have discovered many improvements in existing technologies and techniques that are the subject of the embodiments described herein. Through hard work, ingenuity, and innovation, many of these deficiencies, challenges, and problems have been addressed by developing solutions included in the embodiments of the present disclosure, some examples of which are described in detail herein. Utility Model Content

[0004] Various embodiments described herein relate to electromagnetic shielding for semiconductor packages and / or printed circuit boards.

[0005] According to some embodiments of the present disclosure, an example method is provided. The method can be used to manufacture an electromagnetic shield, and the method can include: providing a substrate with an optical device and an RF cover attached thereto, wherein the RF cover includes a first hole aligned with an optical axis of the optical device; depositing a deposition layer, wherein the deposition layer includes at least a first portion of the deposition layer and a second portion of the deposition layer, wherein the first portion of the deposition layer is deposited across the first hole of the RF cover and includes a second hole narrower than the first hole and aligned with the optical axis, wherein the second portion of the deposition layer is deposited on the RF cover and a first terminal of the substrate, and wherein the first portion of the deposition layer is not connected to the second portion of the deposition layer; curing the deposition layer; and wherein the cured deposition layer is electrically coupled to the RF cover and the first terminal of the substrate to provide a first electromagnetic shield for at least the optical device.

[0006] According to some embodiments of the present disclosure, an example system is provided. The system includes: a substrate; an optical device attached to the substrate; an RF shield attached to the substrate, wherein the RF shield includes a first hole aligned with an optical axis of the optical device; a deposited layer including at least a first portion of the deposited layer and a second portion of the deposited layer, wherein the first portion of the deposited layer is deposited across the first hole of the RF shield and includes a second hole narrower than the first hole and aligned with the optical axis, wherein the second portion of the deposited layer is deposited on the RF shield and a first terminal of the substrate, and wherein the first portion of the deposited layer is disconnected from the second portion of the deposited layer; and wherein the deposited layer is cured and electrically couples the RF shield to the first terminal of the substrate to provide a first electromagnetic shield for at least the optical device.

[0007] In some embodiments, a first semiconductor package is attached to a substrate and positioned at a first distance from an RF shield; wherein the deposited layer includes a third portion deposited on the semiconductor package and at least a second terminal of the substrate; and wherein the cured deposited layer is electrically coupled to the second terminal of the substrate to provide a second electromagnetic shield for at least the semiconductor package.

[0008] In some embodiments, the deposited layer includes copper paste.

[0009] In some embodiments, the deposited layer includes silver paste.

[0010] In some embodiments, the deposited layer includes a dielectric ink.

[0011] In some embodiments, the RF shield comprises metal.

[0012] In some embodiments, the RF shield comprises a non-metallic conductive material.

[0013] In some embodiments, the first portion of the deposited layer is formed in a pattern.

[0014] In some embodiments, the second portion of the deposited layer is formed as a stripe.

[0015] In some embodiments, a first portion of the deposited layer is formed in a first pattern, and a second portion of the deposited layer is formed in a second pattern.

[0016] The above summary is provided merely for the purpose of outlining some example embodiments to provide a basic understanding of some aspects of the present disclosure. Therefore, it will be understood that the above embodiments are merely examples and should not be construed as narrowing the scope or spirit of the present disclosure in any way. It will also be understood that in addition to those embodiments summarized here, the scope of the present disclosure also includes many potential embodiments, some of which will be further described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Having described certain example embodiments of the present disclosure in a general sense, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and in which:

[0018] Figure 1 A cross-sectional diagram illustrating a block diagram of a first system according to one or more embodiments of the present disclosure;

[0019] Figure 2 illustrates a top view of a first embodiment of a first system according to one or more embodiments of the present disclosure;

[0020] Figure 3A-Figure 3B illustrates a top view of a second embodiment of the first system according to one or more embodiments of the present disclosure;

[0021] Figure 4a cross-sectional diagram illustrating a block diagram of a second system according to one or more embodiments of the present disclosure;

[0022] Figure 5 illustrates a top view of a second embodiment of a second system according to one or more embodiments of the present disclosure;

[0023] Figures 6A-6E illustrates an example embodiment of a deposited layer according to one or more embodiments of the present disclosure;

[0024] Figure 7 An example flow chart illustrating operations for manufacturing an electromagnetic shield according to one or more embodiments of the present disclosure; and

[0025] Figure 8 An example flow diagram is illustrated for providing operations of a system according to one or more embodiments of the present disclosure. DETAILED DESCRIPTION

[0026] Some embodiments of the present disclosure will now be described more fully herein with reference to the accompanying drawings, in which some, but not all, embodiments of the present disclosure are shown. Indeed, the various embodiments of the present disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like reference numerals refer to like elements throughout.

[0027] As used herein, the term "comprising" means including but not limited to, and should be interpreted in the manner commonly used in a patent context. The use of broader terms such as "comprises," "includes," and "having" should be understood to provide support for narrower terms such as "consisting of," "consisting essentially of," and "consisting substantially of."

[0028] The phrases "in various embodiments," "in one embodiment," "according to one embodiment," "in some embodiments," etc. generally mean that the particular feature, structure, or characteristic following the phrase may be included in at least one embodiment of the present disclosure, and may be included in more than one embodiment of the present disclosure (importantly, these phrases are not necessarily referring to the same embodiment).

[0029] The word “example” or “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other implementations.

[0030] If the specification states that a component or feature "may," "could," "might," "should," "would," "preferably," "likely," "typically," "optionally," "for example," "often," or "might" (or other such language) be included or have a characteristic, this does not require that particular component or feature be included or have that characteristic. Such a component or feature may optionally be included in some embodiments, or may be excluded.

[0031] The use of the term "circuitry" (as used herein with respect to components of a system or device) should be understood to include specific hardware configured to perform the functions associated with the specific circuits described herein. The term "circuitry" should be broadly interpreted to include hardware and, in some embodiments, software for configuring the hardware. For example, in some embodiments, a "circuitry" may include processing circuitry, communication circuitry, input / output circuitry, and the like. In some embodiments, other elements may provide or supplement the functionality of a particular circuit.

[0032] Overview

[0033] Various embodiments of the present disclosure are directed to improved methods, systems, and apparatus for electromagnetic shielding, particularly for semiconductor package-level apparatuses and / or printed circuit board package-level apparatuses.

[0034] Various semiconductor devices and / or PCB components may require shielding or shielding to prevent electromagnetic interference (EMI) from interfering with their operation and / or causing them to operate inefficiently. This EMI can originate from other components and / or devices, including those located on the same PCB. Shielding prevents EMI from sources external to the shield from interfering with the interior of the shield, including preventing crosstalk between components on the PCB and / or substrate.

[0035] A radio frequency (RF) can be used to shield devices and / or components inside the RF can from EMI from sources outside the RF can. RF cans can shield optical devices (e.g., lasers, image sensors, etc.). However, in order to perform the desired function of the optical device, the optical device requires an aperture in the RF can for the optical path. Such an aperture, based on the size of the aperture in the RF can, weakens the shielding provided by the RF can. Due to one or more operations performed through the RF can aperture (such as electrically coupling the optical device to one or more terminals on a substrate using one or more wire bonds), the size of the aperture in the RF can is set to be larger than the size required for the optical path. Additionally or alternatively, some components can utilize shielding from conformal coatings, but such coatings are applied using non-selective operations (e.g., sputtering, spraying, or plating), which requires multiple steps and an exposed ground plane. Various embodiments may integrate these alternative approaches to EMI shielding, including using them in conjunction with EMI shielding according to one or more embodiments described herein.

[0036] According to the embodiments described herein, various embodiments can utilize a shield formed by a deposited layer. The deposited layer can be applied in one or more operations in which the deposited layer is selectively deposited. The deposited layer does not require a mask or associated operations, which allows for higher manufacturing efficiency. The deposited layer can be selectively applied to one or more components of a semiconductor package, a PCB, and / or a component on a PCB in one or more portions. The deposited layer may include a paste. In various embodiments, the deposition of the portion may include multiple strips and / or patches deposited simultaneously at selected locations. In various embodiments, this may be referred to as pulse printing.

[0037] The deposited layer of various embodiments may include one or more portions that span and / or extend across gaps and / or openings in and / or between a semiconductor package, a PCB, and / or components on the PCB. The deposited layer may also be wrapped around and / or applied to multiple sides of a semiconductor package and / or component on the PCB, including around edges. Additionally or alternatively, multiple deposited portions of a deposited layer may be used to apply multiple strips that overlap with another deposited layer, including without requiring the application of any mask or other layer (e.g., laminate, film, etc.).

[0038] It should be readily understood that the embodiments of the methods, systems, and apparatus described herein may be configured in various additional and alternative ways besides those explicitly described herein.

[0039] Exemplary Systems and Apparatus

[0040]

[0014] Embodiments of the present disclosure herein include systems and apparatus for electromagnetic shielding as described herein, which may be implemented in various embodiments.

[0041] Figure 1 A cross-sectional view of a block diagram of a first system according to one or more embodiments of the present disclosure is illustrated. The first semiconductor package includes a substrate 110 having an optical device 120 attached thereto. The optical device can be, for example, a laser (e.g., LCSP, VCSEL, etc.) or an optical sensor. The optical sensor 120 can be electrically coupled to one or more terminals or signal pads on the substrate 110 via one or more wire bonds 160. The RF cover 130 is attached to the substrate 110 via one or more attachment layers 134 (e.g., glue, epoxy, paste, etc.). The RF cover 130 can be aligned so that the hole 152 of the RF cover 130 is aligned with the optical axis 122 of the optical sensor 120. Thus, the optical device 120 can emit and / or receive light along its optical path. In various embodiments, the hole 150 can be larger than the optical path and / or sized to allow the optical sensor to be mounted and / or attached (e.g., via wire bonds 160) to the substrate 110 after the RF cover 130 is attached to the substrate 110. The deposition layer 140 may include a first portion 142 and / or a second portion 144, the first portion 142 having an aperture 154 narrower than the RF shield aperture 152 (eg, as shown in FIG. 1 ). Figure 2 ), the second portion 144 electrically couples the RF shield to the terminal 112A on the substrate 110.

[0042] The RF shield 130 may provide some EMI shielding, but the aperture 152 in the RF shield 130 may not provide shielding for this portion of the RF shield 130. However, the RF shield 130 may act as a conductor, conducting signals generated in the deposited layer 140 by the shielded EMI to one or more grounds, such as through the RF shield 130, through the second portion 144 of the deposited layer 140, and to the terminal 112A, which may be grounded.

[0043] In various embodiments, the RF shield can be electrically coupled to one or more terminals 112 on the substrate 110. For example, the RF shield 130 can be electrically coupled to the terminal 112B via the attachment layer 134B. The terminal 112B can be configured as a ground plane or configured to be electrically coupled to the ground plane of a larger system. Alternatively, the RF shield 130 can be attached to the substrate 110 at one or more attachment layers 134 that are not electrically coupled to ground. For example, the RF shield 130 can be attached to the substrate 110 at the attachment layer 134A that is not electrically coupled to the terminal 112 of the substrate. However, the terminal 112 can be located on the substrate 110 near the RF shield 130, such as the terminal 112A.

[0044] In various embodiments, substrate 110 , RF shield 130 , and / or other components, systems, and / or circuits on substrate 110 may be subjected to a pre-treatment (eg, plasma treatment) to improve coupling with deposited layer 140 .

[0045] Figure 2 FIG. 1 illustrates a top view of a first embodiment of a first semiconductor package according to one or more embodiments of the present disclosure. Figure 2 As shown, the aperture of the first portion 142 of the deposition layer 140 may include an aperture 154 of the first portion 142 of the deposition layer 140. The aperture 154 of the first portion 142 may be narrower than the aperture 152 of the RF shield.

[0046] The deposition layer 140 may be a paste and / or ink. In various embodiments, the paste may be an epoxy resin and / or ink, such as a dielectric ink. The paste may also be a metal paste (e.g., including copper, silver, etc.). After deposition, the deposition layer 140 may be cured (e.g., sintered, etc.). When the deposition layer 140 is deposited onto the RF cover 130 and / or the substrate 110, the deposition layer 140 may be electrically coupled to the RF cover 130 and / or the substrate 110, including being electrically coupled to one or more terminals 112 of the substrate 110. Thus, the deposition layer may be used to shield the optical sensor 120 from EMI.

[0047] Figure 3A-Figure 3B FIG2 illustrates a top view of a second embodiment of the first system according to one or more embodiments of the present disclosure. The deposition layer 340 may be applied with multiple deposition portions. For example, the first deposition portion may deposit Figure 3A A plurality of strips 344A-D may be deposited in the first deposition layer. A second deposition portion may deposit a second plurality of strips 344E and 344F. The deposition layer including strips 344C, 344D, 344E, and 344F may be formed in a pattern around aperture 152. The pattern of these strips 344C-344F may form aperture 154, which may narrow aperture 152. As will be appreciated, strips 344C-344F may cover one or more portions of aperture 152 where they are not supported by RF shield 130. Additionally, strips 344A and 344B may be deposited along with the first deposition layer. Strips 344A and 344B may electrically couple the RF shield to one or more terminals in substrate 110.

[0048] Figure 4A cross-sectional view of a block diagram of a second system according to one or more embodiments of the present disclosure is illustrated. The second system includes the first system on a substrate 110 and a plurality of additional components on the substrate 110. These components may include a sensor 410A, a semiconductor package 410B (e.g., a WLSCP, etc.), and / or other package or PCB-level components and / or circuits. The sensor 410A may be electrically coupled to one or more terminals (e.g., 112D) on the substrate 110 via one or more wire bonds 162. The semiconductor package 410B may be electrically coupled to one or more terminals 112 (e.g., 112G, 112H) of the substrate 110 via one or more terminals (e.g., 434A, 434B) of the semiconductor package.

[0049] Electrical connections may be provided to the sensor 410A through the third portion 446 of the deposited layer 140. For example, the third portion 446 may be deposited to attach to the sensor 410A (including the terminals) and the terminals 112D of the substrate 110.

[0050] Additionally or alternatively, semiconductor package 410B may lack all or part of the EMI shielding. Deposition layer 140 may be used to provide shielding while other portions of deposition layer 140 are applied. For example, fourth portion 448 of deposition layer 140 may be used to provide shielding for semiconductor package 410B. Fourth portion 448 of deposition layer 140 may completely cover semiconductor package 410B. Fourth portion 448 of deposition layer 140 may be electrically coupled to one or more terminals 112 of substrate 110 (e.g., 112E for the third portion and 112F and 112I for the fourth portion) to ground deposition layer 140 and provide a path for EMI absorption to ground.

[0051] Figure 5 A top view of a second embodiment of the first system according to one or more embodiments of the present disclosure is illustrated. The top view illustrates how third portion 446 can serve as a strip that electrically couples one or more terminals of sensor 410A to one or more terminals 112 (112D) of the substrate. The top view also illustrates how fourth portion 448 can completely cover semiconductor package 410B.

[0052] Figures 6A-6E An example embodiment of a deposition layer according to one or more embodiments of the present disclosure is illustrated. Deposition layer 140 includes a paste layer that can be deposited simultaneously in multiple locations. The multiple locations of the deposition layer do not need to be connected. Therefore, deposition layer 140 can include multiple separately positioned portions (e.g., 142, 144). Furthermore, the shape of each portion of deposition layer 140 can be the same, similar, or different. Figures 6A-6E The diagrams illustrate different embodiments that a portion of the deposition layer 140 may employ. However, it will be understood that the deposition layer 140 may employ other than Figures 6A-6E Other shapes and / or patterns than those shown in .

[0053] Figure 6A Illustrated is a top view of a strip of deposited layer 140. Strip 610 may have a height and a length.

[0054] Figure 6B A top view of a first pattern of the deposition layer 140 is shown. The cross-shaped first pattern 610 may have a first height and a first width.

[0055] Figure 6C The diagram shows a second pattern of the deposition layer 140. The second pattern 630 has a block shape or a strip shape with holes 632.

[0056] Figure 6D A cross-sectional view of a strip used to deposit layer 140 is shown. Strip 640 can have a height that allows strip 640 to have a 3D structure. Strip 640 can span a gap and / or hole created between first side 644A and second side 644B. For example, strip 640 can have a height and span a hole in an RF shield (e.g., 130), which can be a bridge structure.

[0057] Figure 6E A cross-sectional view of a strip of deposited layer 140 is shown. Strips 650 can be deposited simultaneously to attach to one or more surfaces, such as the side and top surfaces of a component (e.g., 654). Alternatively or additionally, strips 650 can be attached around corners and / or edges of a component (e.g., 654).

[0058] In various embodiments, the deposition layer 140 may have a 3D shape and / or structure, which may include a complex 3D shape with air gaps, steps, and / or openings.

[0059] It should be readily understood that the embodiments of the systems and apparatus described herein may be configured in a variety of additional and alternative ways besides those explicitly described herein.

[0060] Exemplary Methods

[0061] Figure 7 An example flow chart illustrating operations for manufacturing an electromagnetic shield in accordance with one or more embodiments of the present disclosure is illustrated.

[0062] At operation 702 , a system is provided. The system may include a substrate 110 with an optical device 120 and an RF cover 130 attached thereto. The optical device 120 may have an optical axis 122 aligned with an aperture 152 of the RF cover 130 .

[0063] At operation 704, a deposition layer is deposited. The deposition layer 140 can be deposited in one or more portions (e.g., 142, 144, etc.). The one or more portions can include a first portion 142 that is deposited in a pattern that partially covers the aperture 152 of the RF shield 130. The first portion 142 can include an aperture 154 that is narrower than the aperture 152 of the RF shield 130. The optical axis 122 of the optical device 120 can also be aligned with the aperture 154 of the first portion 142 of the deposition layer 140. The deposition layer 140 can also include one or more additional portions 144 that are deposited simultaneously with the first portion 142. The second portion 144 can electrically couple the RF shield 130 to one or more terminals 112A of the substrate 110, which can be grounded or configured for grounding.

[0064] At operation 706, the deposit is cured. The deposited layer 140 may be cured, such as by sintering the deposited layer 140. Curing the deposited layer 140 may be by hardening the paste of the deposited layer 140 into a fixed position via sintering.

[0065] Figure 8 An example flow diagram is illustrated for providing operations of a system according to one or more embodiments of the present disclosure.

[0066] At operation 802 , a substrate is provided. The substrate may be substrate 110 .

[0067] At operation 804, the optical device is attached to the substrate. The optical device 120 may be attached to the substrate 110. The optical device 120 may be attached by die attach.

[0068] At operation 806, an RF cover having a hole is attached to the substrate. The RF cover 130 having a hole 154 can be attached to the substrate 110. The hole 154 of the RF cover 130 can be aligned with the optical axis 122 of the optical device 120 to allow the optical device 120 to transmit and / or receive light. The RF cover 130 can be attached using surface mount technology.

[0069] At operation 808, one or more wire bonds are created between the optical device and the substrate through the aperture of the RF cover. One or more wire bonds 160 may be created to electrically couple one or more terminals and / or signal pads of the optical device 120 to one or more terminals and / or signal pads of the substrate 110. The wire bonds may be created through the aperture 152 of the RF cover 130.

[0070] At operation 810 , one or more additional components are attached to the substrate. One or more additional components, such as sensor 410A, semiconductor packages, etc., may be attached to substrate 110 .

[0071] At operation 812 , the exposed surfaces are pre-treated. One or more exposed surfaces of the substrate 110 , RF shield 130 , sensor 410A, semiconductor package 410B, and / or other attached components may be pre-treated, such as using a plasma treatment or the like.

[0072] Various embodiments may omit one or more operations described herein. Additionally or alternatively, various embodiments may repeat one or more operations described herein.

[0073] in conclusion

[0074] The operations and / or functions of the present disclosure have been described herein, such as in flow charts. Although operations and / or functions are illustrated in a particular order in the accompanying drawings, this should not be interpreted as requiring that such operations and / or functions be performed in the particular order shown or in a sequential order, or that all illustrated operations be performed in order to achieve the desired result. In some cases, it may be advantageous to perform the operations and / or functions in an alternative order. In some cases, the acts recited in the claims can be performed in a different order and still achieve the desired result. Therefore, although specific embodiments of the subject matter have been described, other embodiments are within the scope of the subsequent claims.

[0075] Although this specification contains many specific embodiments and implementation details, these should not be interpreted as limitations on the scope of any disclosure or possible claim, but rather as descriptions of specific features of specific disclosed embodiments. Certain features described herein in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented in multiple embodiments individually or in any suitable subcombination. Furthermore, although features may be described above as acting in certain combinations, and even initially claimed as such, one or more features from a claimed combination may in some cases be deleted from that combination, and a claimed combination may be directed to subcombinations or variations of subcombinations.

[0076] Similarly, while operations are illustrated in a particular order in the drawings, this should not be construed as requiring that the operations be performed in the particular order shown, or in sequential order, or that all illustrated operations be performed, in order to achieve the desired results. In some cases, it may be advantageous to use operations in an alternative order. In some cases, the actions recited in the claims can be performed in a different order and still achieve the desired results.

[0077] Although this detailed description sets forth certain embodiments of the disclosure, the appended claims cover other embodiments of the disclosure according to various modifications and improvements other than those described.

[0078] In the following claims, unless a given claim uses the specific terms "means for" or "step for" it is not intended that the claim be interpreted under 35 USC §112, paragraph 6.

Claims

1. A system for electromagnetic shielding, characterized in that: include: substrate; an optical device attached to the substrate; an RF cover attached to the substrate, wherein the RF cover includes a first hole aligned with an optical axis of the optical device; a solidified deposited layer comprising at least a first portion of the deposited layer and a second portion of the deposited layer, wherein the first portion of the deposited layer is disposed across a first aperture of the RF shield and comprises a second aperture that is narrower than the first aperture and aligned with the optical axis, wherein the second portion of the deposited layer is disposed over the RF shield and the first terminal of the substrate, and wherein the first portion of the deposited layer is unconnected to the second portion of the deposited layer; and The deposited layer electrically couples the RF shield to the first terminal of the substrate to provide a first electromagnetic shield for at least the optical device.

2. The system according to claim 1, wherein: wherein the first semiconductor package is attached to the substrate and is located at a first distance from the RF shield; wherein the deposited layer includes a third portion disposed on the semiconductor package and at least a second terminal of the substrate; and wherein the cured deposited layer is electrically coupled to the second terminal of the substrate to provide a second electromagnetic shield for at least the semiconductor package.

3. The system according to claim 1, wherein: The deposited layer includes solidified copper paste.

4. The system according to claim 1, wherein: The deposited layer includes solidified silver paste.

5. The system according to claim 1, wherein: The deposited layer includes a cured dielectric ink.

6. The system according to claim 1, wherein: The RF shield includes metal.

7. The system according to claim 1, wherein: The RF shield includes a non-metallic dielectric material.

8. The system according to claim 1, wherein: The first portion of the deposited layer has a pattern.

9. The system according to claim 1, wherein: The second portion of the deposited layer has a strip shape.

10. The system according to claim 1, wherein: The first portion of the deposited layer has a first pattern, and the second portion of the deposited layer has a second pattern.

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