Wire-bonded electromagnetic interference (EMI) cage to block transmission and reception of EMI at optical transmit components

Abstract

The present disclosure relates to wire bonding electromagnetic interference (EMI) cages to block transmission and reception of EMI at optical transmit components. An example apparatus and an optical emitting device for preventing electromagnetic radiation from being transmitted to and from a target electrical component of an electronic device are provided. The example apparatus may include an optical transmitting assembly electrically connected to the target electrical portion and configured to produce an optical output. The example apparatus may also include a wire-bonded electromagnetic interference cage configured to block electromagnetic emissions from passing therethrough. The wire-bonded electromagnetic interference cage may include a plurality of bonding wires, where each bonding wire is electrically coupled to an electrical ground, and where the wire-bonded electromagnetic interference cage overlies at least a portion of the target electrical portion. In addition, the wire-bonded electromagnetic interference cage may also define an electromagnetic interference cage opening through which the optical output passes.

Description

Technical Field

[0001] Embodiments of the present disclosure relate generally to electromagnetic interference (EMI) shields, and more particularly to EMI shields that include a cage of electrically grounded bond wires. Background Art

[0002] Various example embodiments address technical issues associated with preventing electromagnetic radiation from being sent to and from electrical components of various electronic devices in an electronic system. An electronic system may include many electronic devices that radiate and / or are affected by the radiation of electromagnetic waves. Exposure to EMI may cause electrical devices to generate errors when processing and / or transmitting data, or even cease to operate.

[0003] Applicants have identified many technical challenges and difficulties associated with EMI shields in electronic systems. Through hard work, ingenuity and innovation, Applicants have solved the problems associated with EMI shields in electronic systems by developing solutions embodied in the present disclosure, which are described in detail below. Summary of the invention

[0004] Various embodiments are directed to example apparatus and optical emission devices for preventing electromagnetic radiation from being transmitted to and from electrical components of electronic devices. In some embodiments, the example apparatus may include an optical emission component electrically connected to a target electrical portion and configured to produce an optical output. The example apparatus may also include a wire-bonded electromagnetic interference cage configured to block electromagnetic emissions from passing therethrough. The wire-bonded electromagnetic interference cage includes a plurality of bonding wires, wherein each of the plurality of bonding wires is electrically coupled to an electrical ground, and wherein the wire-bonded electromagnetic interference cage covers at least a portion of the target electrical portion. In addition, the wire-bonded electromagnetic interference cage may also define an electromagnetic interference cage opening through which the optical output passes.

[0005] In some embodiments, the optical launch assembly further includes a first side and a second side opposite the first side, wherein each of the plurality of bonding wires is electrically connected to an electrical ground at a first bonding wire end on the first side of the optical launch assembly, wherein each of the plurality of bonding wires is electrically connected to an electrical ground at a second bonding wire end on the second side of the optical launch assembly, such that each bonding wire passes over a portion of the optical launch assembly, and wherein each bonding wire extends to a maximum wire bond electromagnetic interference cage height.

[0006] In some embodiments, the device also includes a second plurality of bonding wires, wherein the optical launch assembly includes a first end and a second end, wherein each of the second plurality of bonding wires is electrically connected to an electrical ground at the first end of the optical launch assembly, and wherein each of the second plurality of bonding wires is electrically connected to an electrical ground at the second end of the optical launch assembly, such that each of the second plurality of bonding wires passes over a portion of the optical launch assembly that is perpendicular to the plurality of bonding wires.

[0007] In some embodiments, the plurality of bond wires are parallel.

[0008] In some embodiments, the maximum wire bond EMI cage height is the distance from the top of the optical launch assembly to a bond wire among the plurality of bond wires.

[0009] In some embodiments, the maximum wire bond EMI cage height is between 0.050 mm and 0.160 mm.

[0010] In some embodiments, the plurality of bond wires includes at least a first bond wire and a second bond wire, and wherein the first bond wire and the second bond wire cross.

[0011] In some embodiments, the wirebond EMI cage includes a first gap corresponding to a distance between each of the plurality of bond wires, wherein the wirebond EMI cage further includes a second gap defining an EMI cage opening, and wherein the first gap is smaller than the second gap.

[0012] In some embodiments, the first gap is less than or equal to 0.6 mm.

[0013] In some embodiments, a first bond wire end of each of the plurality of bond wires is attached to the electrical ground using a ball bond, and a second bond wire end of each of the plurality of bond wires is attached to the electrical ground using a ball bond or a wedge bond.

[0014] In some embodiments, the optical transmission component includes a vertical cavity surface emitting laser.

[0015] In some embodiments, the target electrical part is susceptible to electromagnetic interference.

[0016] In some embodiments, the wire bond EMI cage blocks EMI from external EMI sources from being transmitted to the target electrical part.

[0017] In some embodiments, the target electrical part generates electromagnetic interference.

[0018] In some embodiments, the wire bond EMI cage blocks the transmission of EMI from the target electrical part.

[0019] In some embodiments, the wire bond EMI cage is configured to block electromagnetic emissions up to 10 GHz.

[0020] An example optical launch device is also provided. In some embodiments, the example optical launch device includes a device housing. In addition, the example optical launch device may also include one or more electrical components disposed on a substrate within the device housing. In some embodiments, the one or more electrical components include an optical launch component that is at least electrically connected to a target electrical portion and configured to produce an optical output. In some embodiments, the one or more electrical components may also include a wire-bonded electromagnetic interference cage disposed within the device housing and configured to block the passage of electromagnetic emissions. In some embodiments, the wire-bonded electromagnetic interference cage includes a plurality of bonding wires, wherein each of the plurality of bonding wires is electrically coupled to an electrical ground, wherein the wire-bonded electromagnetic interference cage covers at least a portion of the target electrical portion, and wherein the wire-bonded electromagnetic interference cage defines an electromagnetic interference cage opening through which the optical output passes.

[0021] In some embodiments, the device housing further includes an optical emission opening aligned with the optical emission assembly and configured to allow the optical output to exit the device housing.

[0022] In some embodiments, the optical emission opening is larger than the electromagnetic interference cage opening.

[0023] In some embodiments, the optical launch assembly further includes a first side and a second side opposite the first side, wherein each of the plurality of bonding wires is electrically connected to an electrical ground at a first bonding wire end on the first side of the optical launch assembly, wherein each of the plurality of bonding wires is electrically connected to an electrical ground at a second bonding wire end on the second side of the optical launch assembly, such that each bonding wire passes over a portion of the optical launch assembly, and wherein each bonding wire extends to a maximum wire bond electromagnetic interference cage height. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Reference will now be made to the drawings. The components shown in the drawings may or may not be present in certain embodiments described herein. According to example embodiments of the present disclosure, some embodiments may include fewer (or more) components than shown in the drawings.

[0025] 1A-1B illustrate example prior art metal can EMI shields for the exterior of a device housing of an electronic device.

[0026] Figure 2A – Figure 2B Illustrated is a perspective view of an example optical launch device including a device housing according to an example embodiment of the present disclosure.

[0027] Figure 3 Illustrated is a perspective view of an example wire bond EMI cage according to an example embodiment of the present disclosure.

[0028] Figure 4 Illustrated is a perspective view of an example wire bond EMI cage overlying a target electrical portion of an optical transmit assembly according to an example embodiment of the present disclosure.

[0029] Figure 5 Illustrated is a perspective view of an example wire bond EMI cage surrounding an example optical transmit assembly in accordance with an example embodiment of the present disclosure.

[0030] Figure 6 Illustrated is a perspective view of an example wire bond EMI cage defining an EMI cage opening that allows for transmission of an optical output in accordance with an example embodiment of the present disclosure.

[0031] Figure 7 Illustrated is a top view of an example EMI cage opening in an example wire bond EMI cage in accordance with an example embodiment of the present disclosure.

[0032] Fig. 8A – Figure 8B Comparison with an Example Metal Can EMI Shield illustrates a side view of an example optical transmit assembly protected by a wire bond EMI cage defining an EMI cage opening to allow transmission of an optical output in accordance with an example embodiment of the present disclosure.

[0033] Fig. 9 Illustrated is a perspective view of an example electrical component protected by an example wire bond EMI cage in accordance with an example embodiment of the present disclosure.

[0034] Fig.10 Illustrated is a perspective view of an example wire bond EMI cage overlying substrate traces in accordance with an example embodiment of the present disclosure.

[0035] Fig.11A – Fig. 11B A further example embodiment of a wire bonded EMI cage according to an example embodiment of the present disclosure is illustrated. DETAILED DESCRIPTION

[0036] Example embodiments will be described more fully below with reference to the accompanying drawings, in which some but not all embodiments of the invention of the present disclosure are shown. Indeed, embodiments of the present disclosure may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure satisfies applicable legal requirements. Like reference numerals refer to like elements throughout.

[0037] Various example embodiments address technical problems associated with preventing destructive electromagnetic radiation from being sent to / received from electrical components contained within various electronic devices of an electronic system. As will be appreciated by those skilled in the art to which the present disclosure pertains, there are many example scenarios in which it may be desirable to block electromagnetic radiation from being sent from an electrical component and / or to prevent an electrical component from receiving electromagnetic radiation.

[0038] For example, electronic systems may include many electrical components that radiate electromagnetic radiation and / or are affected by electromagnetic wave radiation. As electronic systems shrink in size and electrical devices move closer together, errors due to EMI may increase. The EMI problem is further exacerbated by the expectation of higher power electrical devices in electronic systems. As power increases, the adverse effects on electrical components in high-power electronic devices also increase. In addition, higher communication frequencies (for example, 4G to 5G mobile phones transmit at frequencies between 900 megahertz and 5 gigahertz) may cause communication devices to be more susceptible to errors due to EMI. The combination of higher power electrical components and high-frequency communications in closer proximity may cause unwanted crosstalk, coupling and / or mixing, resulting in loss of electronic device performance.

[0039] In some examples, metal can EMI shields are created by stamping stainless steel sheets to create a conductive envelope around the housing of an electronic device that includes one or more electrical components. These metal can EMI shields are generally positioned outside of the electrical component package and attached to a host circuit board to which the electrical component package is attached.

[0040] As shown in FIG. 1A , the example metal can EMI shield 104 cannot closely conform to the shape of the underlying electronic device due to the manufacturing process. For example, the stamping or drawing process prevents the manufacture of the metal can EMI shield 104 with sharp corners. The limitation on the forming of the metal can EMI shield 104 causes the metal can EMI shield 104 to occupy additional space 106 around the electronic device 102. Therefore, the introduction of the metal can EMI shield 104 will increase the overall profile of the existing electronic assembly 102 through the requirement for additional space 106, and may prevent the device manufacturer from further reducing the space occupied by the existing electronic device 102 in the electronic system (e.g., mobile phone, tablet computer, laptop computer, etc.). Therefore, the metal can EMI shield 104 comprising a stamped stainless steel plate utilizes more space on the host circuit board of the electronic system.

[0041] Additionally, as depicted in FIG. 1B , the lack of flexibility in manufacturing the metal can EMI shield 104 results in an inability to conform the metal can EMI shield 104 to the topology and / or shape of the underlying electronic device 108 having more complex contours. To provide electromagnetic radiation protection in such cases, manufacturers may piece together multiple metal can EMI shields 104 , 104 b . Piecing together multiple metal can EMI shields 104 , 104 b may result in gaps 110 in the protective shielding provided by the metal can EMI shields 104 , 104 b . The gaps 110 may allow destructive electromagnetic radiation to escape and / or enter, particularly higher frequency EM waves that are more capable of penetrating smaller shield openings (e.g., gaps 110).

[0042] Further problems have led to attempts to isolate or protect optically emitting devices such as optical ranging sensors from transmitting and / or receiving electromagnetic radiation. Optical ranging sensors generally require an optically emitting area (e.g., an aperture or opening) through which an optical output can be emitted. Therefore, any EMI shield must also provide an opening through which the optical output can pass unimpeded. The EMI shield on the outside of the electrical device housing is farther away from the optically emitting area of ​​the optically emitting device. EMI shields (e.g., metal can EMI shield 104) that are farther away from the optically emitting area of ​​the optically emitting device must be larger to allow the entire light field of the optical output to pass through. Larger openings in the EMI shield allow the transmission and reception of electromagnetic waves, thereby interfering with the operation of susceptible electrical components.

[0043] Various example embodiments described herein utilize various techniques to create a wire bond EMI cage for an optical transmission device, utilizing bond wires to create a Faraday cage, preventing the transmission of electromagnetic radiation through the grounded wire bond EMI cage while simultaneously enabling transmission of an optical output.

[0044] For example, in some embodiments, a wire-bonded EMI cage may be formed using established wire-bonding techniques. In such an embodiment, a bonding wire may be connected to one or more ground pads, thereby providing an electrical ground in the substrate of the electronic device. The bonding wire is then passed over one or more target electrical portions of the electrical component and bonded to the substrate on the opposite side of the electronic device. The process is repeated until multiple bonding wires form a cage around one or more target electrical portions of the electrical component. Such a wire-bonded EMI cage enables substrate and package design engineers to protect EM emitting sources or target electrical portions susceptible to EM within the device housing of an electronic device.

[0045] In some embodiments, a wire bond EMI cage can be configured to protect an optical transmit device that produces an optical output. The wire bond EMI cage can also provide an EMI cage opening that is aligned with the optical transmit area of ​​the optical transmit assembly. The EMI cage opening allows light output from the optical transmit device to pass through while preventing electromagnetic radiation from being sent to and received from the target electrical component. Using bonding wire to create a wire bond EMI cage with an EMI cage opening allows the optical output to pass through the wire bond EMI cage without the wire bond EMI cage interfering with the light field. Because the wire bond EMI cage is in close proximity to the optical transmit assembly, the EMI cage opening can be smaller than previous metal can EMI shields (e.g., metal can EMI shield 104) that use stamped metal shields. The stamped metal can EMI shield is placed on the outside of the electronic device housing, away from the optical transmit assembly, and therefore requires a larger opening to allow the light field of the optical output to pass through.

[0046] In addition, due to the flexibility in forming various wire bonded EMI cage shapes, the wire bonded EMI cage can be tailored to the topology of the underlying optical launch assembly. For example, the wire bonded EMI cage can be designed to fit the contours of the target electrical portion of the underlying optical launch assembly to further prevent the transmission and / or reception of electromagnetic radiation. The flexibility in forming various wire bonded EMI cages can also enable the size and shape of the EMI cage opening to be adjusted based on the underlying optical launch assembly and the desired optical output.

[0047] As further described herein, in some embodiments, a wire bonded EMI cage can be used to prevent electromagnetic radiation from being sent to and received from other electrical components within an electronic system. For example, any electrical component identified as a source of electromagnetic radiation transmission can be enclosed by a wire bonded EMI cage to prevent electromagnetic radiation from interfering with other components on the electronic system. Similarly, any electrical component identified as susceptible to external electromagnetic transmission interference can be shielded by a wire bonded EMI cage that encloses the electrical component. Such electrical components can include any surface mount technology (SMT) electrical components, substrate traces, or other electrical components.

[0048] As a result of the example embodiments described herein and in some examples, the effectiveness of a protective EMI shield around an optical launch assembly can be greatly improved. In addition, the space required to implement a protective EMI shield can be greatly reduced.

[0049] Reference now Figure 2A – Figure 2B , shows an example optical launch device. Figure 2B As depicted in FIG. 1 , the example optical launch device 200 includes a substrate 220 that electrically interconnects a plurality of electrical components 222. Figure 2BAs further depicted in FIG. 2 , electrical components 222 are electrically connected to substrate 220 using wire bonds 224 . Example optical launch device 200 also includes a device housing 202 .

[0050] like Figure 2A As depicted in FIG. 1 , the device housing 202 of the example optical launch device 200 is configured to be attached to a substrate 220 to protect the internal electrical components 222 of the optical launch device 200. Figure 2A As further depicted in FIG. 2 , the device housing 202 includes an optical transmit opening 226 that is aligned with the optical transmit region of the optical transmit assembly to allow transmission of the optical output. The device housing 202 also includes a receiver opening 228 configured to receive optical input into the internal light-sensitive sensor.

[0051] like Figure 2A – Figure 2B As depicted in FIG. 2 , the optical launch device 200 is any device and its associated circuitry configured to produce an optical output (e.g., laser, light, etc.). The optical launch device 200 includes one or more optical launch components (e.g., Figure 4 – The optical emission assembly 440, 540, 640, 740, 840 described in FIG8 ) includes an optical emission region configured to direct an optical output. In some embodiments, the optical emission device 200 may include a vertical cavity surface emitting laser (VCSEL) configured to output a laser optical output.

[0052] The optical launch device 200 also includes a plurality of electrical components 222. The electrical component 222 is any discrete physical entity that receives an electrical input and applies a function that affects the received electrical input. The electrical component 222 may include, but is not limited to, wires, switches, capacitors, resistors, inductors, diodes, transistors, bridges, or any combination thereof. In some embodiments, the electrical component 222 may include a surface mount technology (SMT) stand-alone component. The SMT electrical component 222 is mounted directly to a conductive pad on the surface of the substrate 220.

[0053] In some embodiments, electrical component 222 can be electrically connected to substrate 220 using wire bonds 224. Wire bonding is a method for creating an electrical connection between a conductive portion (e.g., a pad) on substrate 220 (e.g., a printed circuit board) and an electrical input and / or output of electrical component 222. Wire bonds can include aluminum, copper, silver, gold, or other similar conductive materials. In some embodiments, wire bonds 224 can be created using a ball bonding technique (e.g., ball bonding), in which a ball at the end of wire bond 224 is welded to the surface of substrate 220 using a combination of pressure, heat, and ultrasonic energy. In some embodiments, wire bonds 224 can be created using a wedge bonding technique (e.g., wedge bonding), in which wire bonds 224 are created in a directional manner by applying pressure to pads on substrate 220.

[0054] In some embodiments, the optical launch device 200 may connect electrical components 222 via substrate traces within the substrate 220. Substrate traces are conductive conduits created within the substrate 220 material to provide electrical connections between electrical components 222 of the optical launch device 200. In some embodiments, the substrate traces may be routed under the solder mask of the substrate 220.

[0055] In some embodiments, the optical transmitting device 200 may also include a light-sensitive receiving electrical component configured to receive the reflected optical output. For example, the optical transmitting device may include a proximity sensor or a similar device configured to transmit an optical output to a target, receive the optical output reflected from the target, and determine one or more distances based on the received optical output.

[0056] like Figure 2A – Figure 2B As further depicted in FIG. 1 , the optical launch device 200 includes a device housing 202. The device housing 202 may be any package, cover, container, or other covering configured to protect the internal electrical components 222 of the optical launch device 200. In some embodiments, the device housing 202 may also include conductive pins and / or conductive pads to provide electrical connections to the internal electrical components 222. The device housing 202 may include plastic, ceramic, or other protective non-conductive materials.

[0057] like Figure 2A – Figure 2BAs further depicted in FIG. 2 , the device housing 202 includes an optical transmit opening 226 and a receiver opening 228. The openings in the device housing 202 can allow optical signals to flow into and out of the optical transmit device 200. For example, the optical transmit opening 226 can be aligned with an optical transmit region of an optical transmit assembly. Optical output from the optical transmit assembly can pass through the optical transmit opening 226 toward a desired target. Similarly, the receiver opening 228 can allow optical signals to be received into the optical transmit device 200, for example, by a photosensitive receiver and analyzed by a processor or other device.

[0058] Reference now Figure 3 , an example wire bonded EMI cage 300 is provided. Figure 3 As depicted in , the example wire bond EMI cage 300 includes one or more grounded bond wires 330. The grounded bond wires 330 at least partially surround the electrical component 322 and are attached using a wire bonding technique. The bond wires may include aluminum, copper, silver, gold, or other similar conductive materials. In some embodiments, the grounded bond wires 330 may be attached using a ball bonding technique, in which a combination of pressure, heat, and ultrasonic energy is used to weld the balls at the ends of the grounded bond wires 330 to the surface of the substrate 320 or the ground plate 332. In some embodiments, the grounded bond wires 330 may be created using a wedge bonding technique, in which the wire bonds 224 are created in a directional manner by applying pressure to pads on the substrate 320 or the ground plate 332.

[0059] In some embodiments, grounded bond wires 330 are attached to substrate 320 at a ground plane 332 (e.g., electrical ground) on a first side of electrical component 322 and pass over electrical component 322 to be attached to ground plane 332 on a second side of electrical component 322. One or more grounded bond wires 330 form a Faraday cage around electrical component 322, preventing internal electromagnetic emissions 338 from being transmitted to the exterior of wire bond EMI cage 300 and preventing external electromagnetic emissions 336 from entering wire bond EMI cage 300.

[0060] like Figure 3 As depicted in , the example wire bond EMI cage 300 is configured to enclose one or more electrical components 322. In some embodiments, the electrical components 322 may be susceptible to interference from external electromagnetic emissions 336. For example, the electrical components 322 may be configured to send and receive data. The external electromagnetic emissions 336 may corrupt the data during processing or transmission, or may even cause the electrical components 322 to cease operation. An example electrical component 322 that is susceptible to interference from external electromagnetic emissions 336 is a communication antenna. In addition, as communication frequency rates and data rates increase, communication antennas become more susceptible to errors caused by external electromagnetic emissions 336.

[0061] The wire bonding EMI cage 300 can be configured to envelop an electrical component 322 susceptible to external electromagnetic emissions 336 to protect the electrical component 322 from the external electromagnetic emissions 336. The external electromagnetic emissions 336 can be any electromagnetic radiation and / or electromagnetic field waves that propagate through space. In some embodiments, the external electromagnetic emissions 336 can come from various electrical components within the same electronic device (e.g., optical transmitting device 200) or electronic system. In some embodiments, the external electromagnetic emissions 336 may come from a source external to the electronic system.

[0062] In some embodiments, electronic components 322 may be identified as electromagnetic radiation emitting components. Such electronic components 322 may emit internal electromagnetic emissions 338. Internal electromagnetic emissions 338 may interfere with the operation of other electrical components.

[0063] Thus, the wire bond EMI cage 300 can be configured to envelop the electrical component 322 identified as generating the internal electromagnetic emissions 338. In this case, the wire bond EMI cage 300 can prevent the internal electromagnetic emissions 338 from leaving the wire bond EMI cage 300.

[0064] like Figure 3 As depicted in FIG. 1 , the grounded bonding wire 330 comprising the wire bond EMI cage 300 forms a Faraday cage. A Faraday cage is a continuous covering comprising a conductive material configured to prevent the transmission of electromagnetic radiation through the cage. The Faraday cage effectively cancels the effects of an incoming or outgoing electric field by distributing the charge of the electric field within the conductive material comprising the cage (e.g., the grounded bonding wire 330). The conductive material comprising the Faraday cage is grounded to dissipate any current generated by the electric field, thereby blocking the transmission of electromagnetic radiation through the Faraday cage.

[0065] Reference now Figure 4 , an example optical transmission assembly 440 protected by an example wire bond EMI cage 400 is provided. Figure 4 As depicted in FIG. 4 , the example wire bond EMI cage 400 includes a plurality of grounded bond wires 430 mounted at each end to a ground plate 432 and covering a target electrical portion 442. The example optical transmission assembly 440 also includes an optical transmission area 444 that is not covered by the wire bond EMI cage 400. Figure 4 As further depicted in FIG. 4 , optical launch assembly 440 is attached to substrate 420 .

[0066] like Figure 4, an example optical launch assembly 440 includes an optical launch area 444 and a target electrical portion 442. The optical launch area 444 is any hole, gap, slit, aperture, or other opening configured to direct the optical output from the optical launch assembly 440. In some embodiments, the optical launch area 444 may be accompanied by a lens or other optical device configured to help direct the optical output of the optical launch assembly 440. The space above the optical launch area 444 is not covered by any wire bonded EMI cage 400, cover, shield, or device housing, thereby allowing the optical output to leave the optical launch device unimpeded.

[0067] like Figure 4 As further depicted in FIG. 4 , the example optical transmission assembly 440 includes a target electrical portion 442. The target electrical portion 442 is any portion of any electrical component (e.g., the optical transmission assembly 440) that is identified as emitting destructive electromagnetic radiation and / or being susceptible to interference from external electromagnetic radiation. In some embodiments, the target electrical portion 442 can be identified as an emitter of destructive electromagnetic radiation and / or susceptible to interference from electromagnetic radiation through simulation and / or testing. Non-limiting examples of target electrical portions 442 that are identified as sources of destructive electromagnetic radiation are as follows: Figure 4 . These wires provide the necessary power for the optical output generating circuit system of the optical transmitting assembly. As the data rate and power of the optical output generating circuit system increase, the amount of destructive electromagnetic radiation emitted from the wires that provide the necessary power may also increase. Other example sources of destructive electromagnetic radiation may include any high-powered or high-data rate SMT electrical components, wires that transmit power and / or data, substrate traces, and other similar electrical components. Non-limiting examples of electrical components that are susceptible to interference from external electromagnetic radiation may include transceiver antenna electrical components, SMT electrical components, data transmission substrate traces, and other similar electrical components.

[0068] like Figure 4 As further depicted in FIG. 1 , the example wire bond EMI cage 400 includes a plurality of grounded bond wires 430. Figure 3 As depicted, the grounded bond wire 430 is any wire comprising aluminum, copper, silver, gold or other similar conductive material and is attached to the surface of the substrate 420 or ground plate 432 using wire bonding techniques. The grounded bond wire 430 is configured to at least partially surround the target electrical portion 442. Additionally, the grounded bond wire 430 is positioned so as not to interfere with the optical output of the optical transmission assembly 440.

[0069] The one or more grounded bond wires 430 form a Faraday cage around the target electrical part 442 , thereby preventing electromagnetic radiation from being transmitted through the wire bond EMI cage 400 into or out of the wire bond EMI cage 400 .

[0070] Reference now Figure 5 , an example wire bonded EMI cage 500 is provided. Figure 5 As depicted in FIG. 1 , the example wire bond EMI cage 500 includes a plurality of grounded bond wires 530 attached to a ground plate 532 and extending over a portion of an optical launch assembly 540. The wire bond EMI cage 500 further defines an EMI cage opening 550 proximate to and aligned with an optical launch region 544 of the optical launch assembly 540 such that optical output passes through the EMI cage opening 550. The optical launch assembly also includes a target electrical portion 542. As shown in FIG. Figure 5 As further depicted in FIG. 5 , optical emission assembly 540 is attached to substrate 520 .

[0071] like Figure 5 As depicted in FIG. 5 , the example wire-joined EMI cage 500 defines an EMI cage opening 550. The EMI cage opening 550 is any hole, gap, or window positioned adjacent to and aligned with the optical emission region 544 of the optical emission assembly 540 so that the optical output of the optical emission assembly 540 can exit the wire-joined EMI cage 500 unimpeded. Figure 6 – FIG. 8 further depicts the EMI cage opening 550 .

[0072] like Figure 5 As further depicted in FIG. 5 , the wire bond EMI cage 500 is positioned at a wire bond EMI cage height 546, which is measured from the top surface of the optical emission region 544 of the optical emission assembly 540 to the bottom surface of the nearest grounded bond wire 530. As the wire bond EMI cage height 546 decreases, the size of the EMI cage opening 550 may also decrease. As the EMI cage opening 550 decreases, fewer electromagnetic radiation emissions are allowed to pass through the wire bond EMI cage 500 to and from the target electrical part 542. In some embodiments, the wire bond EMI cage height 546 can be affected by the maximum wire bond EMI cage height to limit the size of the EMI cage opening 550 and prevent electromagnetic radiation from entering and leaving the wire bond EMI cage 500. In some embodiments, the wire bond EMI cage height is routed between 0.050 mm and 0.160 mm above the shielded component.

[0073] Reference now Figure 6 , an example wire bonded EMI cage 600 is provided. Figure 6 As depicted in FIG. 1 , the example wire bond EMI cage 600 includes a plurality of grounded bond wires 630 configured to prevent electromagnetic radiation from being transmitted to or from a target electrical portion 642 of an optical transmission assembly 640. In addition, the wire bond EMI cage 600 defines an EMI cage opening 650 positioned to enable an optical output 660 to pass through the wire bond EMI cage 600 unimpeded. Figure 6 As further depicted in FIG. 6 , each grounded bonding wire 630 of the wire bond EMI cage 600 is attached to a ground plate 632. Figure 6 As further depicted in FIG. 6 , the optical launch assembly 640 is attached to the substrate 620 .

[0074] like Figure 6 , the wire bond EMI cage 600 includes an EMI cage opening 650 that enables an optical output 660 to pass through the wire bond EMI cage 600. The optical output 660 can be any lighting output, such as visible light, ultraviolet light, infrared light, a laser beam, or other optical lighting. The optical output 660 can be directed by the geometry of the optical emission area 644, a lens, or other optical device configured to direct the optical output 660 toward a target. In addition, various physical characteristics of the optical output 660 can be adjusted, for example, the frequency / wavelength and the power or amplitude can be adjusted based on the intended use of the optical output 660.

[0075] In addition, the optical output 660 may include an illumination light field 662. The illumination light field 662 is the area illuminated by the optical output 660 defined based on the divergence angle of the optical output 660 from the optical emission area 644. For example, in some embodiments, the illumination light field 662 may be 31 degrees, meaning that the optical output 660 diverges from the optical emission area 644 at an angle of 31 degrees in one or more directions. Therefore, as the optical output 660 travels farther from the optical emission area 644, the cross-sectional area of ​​the optical output 660 increases, meaning that the farther the EMI cage opening 650 is from the optical emission area 644, the larger the EMI cage opening 650 must be to allow the entire illumination light field 662 of the optical output 660 to pass unimpeded. In some embodiments, the illumination light field 662 may include a non-circular shape. In such embodiments, the divergence angle varies in different directions.

[0076] Reference now Figure 7 , depicts a top view of an example wire bonded EMI cage 700. Figure 7 As shown in FIG. 1 , the exemplary wire bond EMI cage 700 includes a plurality of grounded bond wires 730a, 730b that enclose portions of an underlying optical launch assembly 740, including a target electrical portion 742 of the optical launch assembly 740. Figure 7 As further depicted in FIG. 1 , the wire bond EMI cage 700 defines an EMI cage opening 750 aligned with the optical emission region 744 of the optical emission assembly 740. The EMI cage opening 750 is defined by an EMI cage opening gap height 770 between the second set of grounded bond wires 730 b and an EMI cage opening gap width 772 between the first set of grounded bond wires 730 a, and each dimension of the EMI cage opening 750 is greater than an EMI cage gap 774 of the wire bond EMI cage 700.

[0077] like Figure 7 , the optical transmission assembly 740 has a first dimension (e.g., length 776) and a second dimension (e.g., width 778). The wire bond EMI cage 700 includes a first set of grounded bond wires 730a (e.g., a plurality of bond wires) configured to be attached to a ground plate 732 and overlie the optical transmission assembly 740 parallel to a width 778 of the optical transmission assembly 740. In addition, the wire bond EMI cage 700 includes a second set of grounded bond wires 730b (e.g., a second plurality of bond wires) configured to be attached to a ground plate 732 and overlie the optical transmission assembly 740 parallel to a length 776 of the optical transmission assembly 740. Thus, the second set of grounded bond wires 730b perpendicularly cross the first set of grounded bond wires 730a, thereby closing a potential gap in the wire bond EMI cage 700 structure through which electromagnetic radiation can escape or enter.

[0078] like Figure 7 As further depicted in FIG. 1 , a first set of grounded bond wires 730 a of the wire bond EMI cage 700 are attached in parallel with adjacent grounded bond wires 730 a and are spaced apart according to an EMI cage gap 774. To prevent the transmission of electromagnetic radiation through the wire bond EMI cage 700, the EMI cage gap 774 is configured based on the frequency and / or wavelength of the electromagnetic radiation to be blocked. For example, the EMI cage gap 774 is at least smaller than the wavelength of the electromagnetic radiation to be blocked. Thus, for electromagnetic radiation with a frequency of 10 GHz and a wavelength of 30 mm, the EMI cage gap 774 can be less than 30 mm to prevent electromagnetic radiation of 10 GHz or less from passing through the wire bond EMI cage 700.

[0079] However, for effective shielding, in some embodiments, the EMI cage gap 774 can be 1 / 50 of the highest frequency wavelength of the electromagnetic radiation to be blocked, where the ratio of 1 / 50 is a general rule of thumb that can vary based on the shielding design goals. Returning to our example for 10 GHz electromagnetic radiation, 1 / 50 of the wavelength of a 10 GHz wave is approximately 0.6 mm. Therefore, in some embodiments, for effective shielding of 10 GHz electromagnetic radiation, the EMI cage gap 774 can be 0.6 mm or less.

[0080] like Figure 7As further depicted in FIG. 7 , the EMI cage opening 750 is defined by an EMI cage opening gap height 770 and an EMI cage opening gap width 772. The EMI cage opening gap height 770 and the EMI cage opening gap width 772 are both greater than the EMI cage gap 774 defined between the first set of grounded bond wires 730a. The larger EMI cage opening gap height 770 and the EMI cage opening gap width 772 allow the illumination light field of the optical output (e.g., optical output 660) to pass through the wire bond EMI cage 700 unimpeded. In some embodiments, the distances of the EMI cage opening gap height 770 and the EMI cage opening gap width 772 can be equal.

[0081] Reference now Fig. 8A and Figure 8B , a wire bond EMI cage 800 is shown positioned within an equipment housing 802 , as compared to, for example, the metal can EMI shield 804 described with respect to FIG. 1 .

[0082] like Fig. 8A As depicted in FIG. 8 , the wire bond EMI cage 800 includes a plurality of bond wires 830 bonded to ground, which are attached to a substrate 820 and overlie an optical emission assembly 840. The wire bond EMI cage 800 includes an EMI cage opening 850 aligned with an optical emission region 844 of the optical emission assembly 840, thereby allowing the entire illumination light field 862 to pass through the wire bond EMI cage 800 unimpeded. Fig. 8A As depicted in FIG. 8 , the wire bond EMI cage 800 is positioned within an equipment housing 802 of an optical transmit device, thereby making the EMI cage opening gap 882 in the wire bond EMI cage 800 smaller.

[0083] like Figure 8B As depicted in FIG. 8 , the metal can EMI shield 804 is positioned outside of the device housing 802 of the optical launch device. Therefore, in order to allow the entire illumination light field 862 to pass through the metal can EMI shield 804 unimpeded, the metal can opening gap 884 of the metal can opening 880 may be larger than when placed within the device housing 802.

[0084] like Fig. 8A and Figure 8B As depicted in FIG. 8 , the optical output 860 of the optical emission assembly 840 is emitted at an angle from the optical emission region 844 of the optical emission assembly 840, thereby creating an illumination light field 862 that becomes wider as the distance from the optical emission region 844 increases. Fig. 8A ) is compared to the metal can EMI shield 804 (as shown in Figure 8B) is further from the optical emission region 844. Therefore, in order to allow the entire illumination light field 862 to pass unimpeded, the metal can opening gap 884 of the metal can EMI shield 804 may be larger than the EMI cage opening gap 882 of the wire bond EMI cage 800 when the optical output 860 is the same.

[0085] Reference now Fig. 9 , depicts an example wire bond EMI cage 900 overlying an example SMT electrical component 990 (eg, a target electrical part). Fig. 9 As depicted in FIG. 1 , the example wire bond EMI cage 900 includes a plurality of grounded bond wires 930 in a non-linear configuration attached to a ground plate 932 and extending over the surface of an SMT electrical component 990. Fig. 9 As further depicted in FIG. 9 , a nearby electromagnetic emission electrical component 992 is emitting external electromagnetic emission 936. SMT electrical component 990 and electromagnetic emission electrical component 992 are further shown attached to substrate 920.

[0086] like Fig. 9 As depicted in FIG. 1 , the design flexibility of the wire bond EMI cage 900 including the grounded bond wires 930 enables the wire bond EMI cage 900 to be placed around electrical components of various shapes, sizes, and types. Fig. 9 As depicted in , the wire bond EMI cage 900 can be designed with a non-linear pattern of grounded bond wires 930 of various heights so that the wire bond EMI cage 900 can closely match the contour of the underlying electrical component (e.g., SMT electrical component 990). Closely matching the contour of the underlying electrical component can reduce the space occupied by the wire bond EMI cage 900 and provide better protection against penetration of external electromagnetic emissions 936. Although in Fig. 9 9 as overlying a SMT electrical component 990, but the non-linear wire bond EMI cage 900 that matches the contour of the underlying electrical component may be used on any electrical component that is identified as emitting destructive electromagnetic radiation and / or is susceptible to interference from external electromagnetic radiation (e.g., external electromagnetic emission 936).

[0087] Reference now Fig.10 , an example wire bond EMI cage 1000 is provided, which includes a plurality of grounded bond wires 1030 attached to a ground plate 1032 in a substrate 1020 of an electronic device. Fig.10 As depicted in FIG. 1 , grounded bond wires 1030 extend over substrate traces 1010 (eg, a target electrical part), thereby preventing electromagnetic radiation from entering or exiting wire bond EMI cage 1000 .

[0088] like Fig.10As depicted in , a wire bond EMI cage 1000 including grounded bond wires 1030 can be used to protect electrical components within a substrate 1020 of an electronic device, such as substrate traces 1010. Electrical components within the substrate 1020 of the electronic device can be identified as emitting destructive electromagnetic radiation and / or susceptible to interference from external electromagnetic radiation through simulation, testing, or other means. The wire bond EMI cage 1000 can be positioned to overlie such electrical components. Identifying electrical components that are sources of electromagnetic radiation or susceptible to interference from electromagnetic radiation and placing the wire bond EMI cage 1000 directly near the electrical components can reduce the space occupied by the EMI shield configured to protect the entire electrical device.

[0089] Reference now Fig.11A , an example wire bonded EMI cage 1100a including non-parallel grounded bond wires 1130 is provided. Fig.11A As depicted in , a plurality of grounded bond wires 1130 are attached to a ground plate 1132 and extend over a target electrical portion 1142 of an optical launch assembly 1140 , crossing a portion of the plurality of grounded bond wires 1130 .

[0090] like Fig.11A As depicted in , the wire-bonded EMI cage including bonding wires enables the definition of various patterns of wire-bonded EMI cages. For example, crossing one or more grounded bonding wires 1130 can close gaps in the wire-bonded EMI cage 1100a exposed by parallel bonding wires. In addition, crossing the bonding wires can enable the wire-bonded EMI cage 1100a to closely match the contour of the optical transmission assembly 1140, thereby reducing the space occupied by the wire-bonded EMI cage 1100a. Although in Fig.11A 1140 as primarily overlying the target electrical portion 1142 , the wire bond EMI cage 1100 a may be extended to create EMI cage openings (eg, EMI cage openings 550 , 650 , 750 , 850 ) around the optical transmit area of ​​the optical transmit assembly 1140 .

[0091] Reference now Fig. 11B , an example wire-bonded EMI cage 1100b including bond wires 1130 having grounds of varying heights is provided. Fig. 11B As depicted in FIG. 1 , a plurality of grounded bond wires 1130 are attached to a ground plate 1132 and extend over a target electrical portion 1142 of an optical launch assembly 1140. The height of each grounded bond wire 1130 is configured to match the contour of the optical launch assembly 1140.

[0092] like Fig. 11BAs depicted in , the wire-bonded EMI cage including bonding wires enables the creation of various wire-bonded EMI cages with different heights. For example, adjusting the height of each grounded bonding wire 1130 to match the contour of the underlying optical launch assembly can close the gap in the wire-bonded EMI cage 1100b exposed by the bonding wires having uniform heights. In addition, changing the height of the bonding wires comprising the wire-bonded EMI cage 1100a to closely match the contour of the optical launch assembly 1140 can reduce the space occupied by the wire-bonded EMI cage 1100b. Although in Fig. 11B Although depicted as primarily overlying the target electrical portion 1142 , the wire bond EMI cage 1100 b may be extended to create EMI cage openings (eg, EMI cage openings 550 , 650 , 750 , 850 ) around the optical transmit area of ​​the optical transmit assembly 1140 .

[0093] Although this detailed description has set forth some embodiments of the invention, the appended claims cover other embodiments of the invention that differ from the described embodiments according to various modifications and improvements. For example, those skilled in the art will recognize that these principles can be applied to any electronic component that emits electromagnetic radiation and / or is susceptible to interference from external electromagnetic radiation.

[0094] In the following claims, unless the specific terms "means for" or "step for" are used within a given claim, it is not intended that the claim be interpreted under 35 USC 112, paragraph 6.

[0095] The use of broader terms such as "including," "comprising," and "having" should be understood to support narrower terms such as "consisting of," "consisting essentially of," and "consisting essentially of." The use of terms such as "optionally," "may," "might," and "could" with respect to any element of an embodiment means that the element is not required, or, alternatively, the element is required, both options are within the scope of the embodiment(s). Moreover, reference to examples is for illustrative purposes only and is not intended to be exclusive.

Claims

1. A device comprising: an optical transmitting assembly configured to generate an optical output, wherein the optical transmitting assembly is electrically connected to a target electrical part; and A wire bonded electromagnetic interference cage configured to block electromagnetic emissions therethrough, comprising: a plurality of bond wires, wherein each bond wire of the plurality of bond wires is electrically coupled to an electrical ground; wherein the wire bonded EMI cage covers at least a portion of the target electrical portion, and Wherein the wire bonded EMI cage defines an EMI cage opening through which the optical output passes.

2. The device according to claim 1, wherein: The optical launch assembly further includes a first side and a second side opposite to the first side, wherein each of the plurality of bonding wires is electrically connected to an electrical ground at a first bonding wire end on a first side of the optical transmission component, wherein each of the plurality of bonding wires is electrically connected to an electrical ground at a second bonding wire end on a second side of the optical launch assembly such that each bonding wire passes over a portion of the optical launch assembly, and Wherein each bonding wire extends to a maximum wire bonding EMI cage height.

3. The apparatus according to claim 2, further comprising: a second plurality of bonding wires, Wherein, the optical transmitting assembly comprises a first end and a second end, wherein each of the second plurality of bonding wires is electrically connected to an electrical ground on the first end of the optical transmitting assembly, and Each of the second plurality of bonding wires is electrically connected to an electrical ground on a second end of the optical launch assembly, such that each of the second plurality of bonding wires passes over a portion of the optical launch assembly that is perpendicular to the plurality of bonding wires.

4. The device according to claim 2, wherein: The plurality of bonding wires are parallel.

5. The device according to claim 2, wherein: The maximum wire bond EMI cage height is a distance from the top of the optical launch assembly to a bond wire among the plurality of bond wires.

6. The device according to claim 5, wherein: The maximum wire bond EMI cage height is between 0.050 mm and 0.160 mm.

7. The device according to claim 2, wherein: The plurality of bonding wires include at least a first bonding wire and a second bonding wire, and The first bonding line intersects with the second bonding line.

8. The device according to claim 2, wherein: The wire bond EMI cage includes a first gap corresponding to a distance between each of the plurality of bond wires, wherein the wire-bonded EMI cage further comprises a second gap defining an opening of the EMI cage, and Wherein, the first gap is smaller than the second gap.

9. The device according to claim 8, wherein: The second gap is less than or equal to 0.6 mm.

10. The device according to claim 2, wherein: A first bond wire end of each of the plurality of bond wires is attached to an electrical ground using a ball bond, and a second bond wire end of each of the plurality of bond wires is attached to the electrical ground using a ball bond or a wedge bond.

11. The device according to claim 1, wherein: The optical transmission component includes a vertical cavity surface emitting laser.

12. The device according to claim 1, wherein: The target electrical part is susceptible to electromagnetic interference.

13. The device according to claim 12, wherein: The wire bond EMI cage blocks EMI from external EMI sources from being transmitted to the target electrical part.

14. The device according to claim 1, wherein: The target electrical part generates electromagnetic interference.

15. The device according to claim 14, wherein: The wire bond EMI cage blocks EMI transmission from the target electrical part.

16. The device according to claim 1, wherein The wire bond EMI cage is configured to block electromagnetic emissions up to 135 GHz.

17. An optical transmitting device, comprising: Equipment housing; One or more electrical components disposed on a substrate within the device housing, the one or more electrical components comprising at least: an optical transmitting assembly configured to generate an optical output, wherein the optical transmitting assembly is electrically connected to a target electrical part; and A wire-bonded electromagnetic interference cage disposed within the device housing and configured to block passage of electromagnetic emissions, comprising: a plurality of bond wires, wherein each bond wire of the plurality of bond wires is electrically coupled to an electrical ground; wherein the wire bonded electromagnetic interference cage covers at least a portion of the target electrical portion, and Wherein the wire bonded EMI cage defines an EMI cage opening through which the optical output passes.

18. The optical launch device of claim 17, the device housing further comprising an optical launch opening aligned with the optical launch assembly and configured to allow the optical output to exit the device housing.

19. The optical transmitting device according to claim 18, wherein: The optical emission opening is larger than the electromagnetic interference cage opening.

20. The optical transmitting device according to claim 17, wherein: The optical launch assembly further includes a first side and a second side opposite to the first side, wherein each of the plurality of bonding wires is electrically connected to an electrical ground at a first bonding wire end on a first side of the optical transmission component, wherein each of the plurality of bonding wires is electrically connected to an electrical ground at a second bonding wire end on a second side of the optical launch assembly such that each bonding wire passes over a portion of the optical launch assembly, and Wherein each bonding wire extends to a maximum wire bonding EMI cage height.

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