PATENT DOCUMENT

Publication Number: US-9583445-B2
Application Number: US-201414218384-A
Country: US
Kind Code: B2

Title: Metal electromagnetic interference (EMI) shielding coating along an edge of a ceramic substrate

Abstract:
An electrical component may be mounted on a substrate such as a ceramic substrate. Contacts may be formed on upper and lower surfaces of the substrate. The electrical component may be soldered to the contacts on the upper surface. The contacts on the lower surface may be used to solder the substrate to a printed circuit. During manufacturing, it may be desirable to use metal traces on a ceramic panel to make connections to contacts on the substrate. Following singulation of the ceramic panel to form the ceramic substrate, some of the metal traces may run to the edge of the ceramic substrate. A folded tab of the printed circuit may form a shield that covers these exposed traces. A divided metal-coated groove or a row of divided metal-coated vias running along each edge of the substrate may also provide shielding.

Claims:
What is claimed is: 
     
       1. Apparatus, comprising:
 a printed circuit; 
 a substrate mounted on the printed circuit, wherein the substrate includes a via; and 
 an electrical component mounted on the substrate, wherein the substrate has an outer-most edge, the outer-most edge comprises an outer-most surface and an additional surface, the additional surface at least partially defines a recess in the outer-most edge, a metal coating is formed on the additional surface, the outer-most surface and the additional surface at least partially define a perimeter of the substrate, the via is formed separately from and electrically isolated from the metal coating, and the via is shielded by the metal coating. 
 
     
     
       2. The apparatus defined in  claim 1 , wherein the additional surface is not parallel to the outer-most surface. 
     
     
       3. Apparatus, comprising:
 a ceramic substrate having an upper surface and an opposing lower surface and having vias that couple contacts on the upper surface to contacts on the lower surface; 
 an integrated circuit soldered to the ceramic substrate, wherein the ceramic substrate is coated with metal edge shielding on an outer-most edge of the ceramic substrate and the outer-most edge couples the upper surface of the ceramic substrate to the lower surface of the ceramic substrate; and 
 at least one divided groove that extends along the outer-most edge, wherein the metal edge shielding is formed on the divided groove, at least one via of the vias is formed in the ceramic substrate adjacent to the metal edge shielding, the at least one via is formed separately from the metal edge shielding, the divided groove is separated from a corner of the substrate by a gap, the ceramic substrate has at least one trace that extends from the at least one via to the outer-most edge in the gap, and the at least one trace is shielded by the metal edge shielding. 
 
     
     
       4. The apparatus defined in  claim 3 , wherein the divided groove has first and second opposing sides, wherein the first side is separated from the corner of the substrate by the gap, and wherein the second side is adjacent to an additional corner of the substrate. 
     
     
       5. The apparatus defined in  claim 4 , wherein no traces are formed between the second side of the divided groove and the additional corner. 
     
     
       6. The apparatus defined in  claim 3 , wherein the at least one via and the at least one trace are not shorted to the metal edge shielding. 
     
     
       7. Apparatus, comprising:
 a printed circuit; 
 a substrate mounted on the printed circuit, wherein the substrate has a perimeter at least partially defined by an outer-most edge surface; 
 an electrical component mounted on the substrate, wherein a groove through the substrate is formed along the outer-most edge surface, the groove has a surface that is substantially parallel to the outer-most edge surface and offset from the outer-most edge surface, and a metal coating is formed on the surface of the groove; 
 a contact on an upper surface of the substrate, wherein the electrical component is soldered to the contact on the upper surface; 
 a contact on a lower surface of the substrate, wherein the printed circuit is soldered to the contact on the lower surface; and 
 a via that is electrically isolated from the metal coating that couples the contact on the upper surface of the substrate to the contact on the lower surface of the substrate, wherein the contact on the upper surface, the contact on the lower surface, and the via are positioned behind and shielded by the metal coating. 
 
     
     
       8. The apparatus defined in  claim 7  wherein the substrate comprises a ceramic substrate. 
     
     
       9. The apparatus defined in  claim 8  wherein the electrical component comprises an integrated circuit. 
     
     
       10. The apparatus defined in  claim 8  further comprising metal traces that extend to the outer-most edge surface in a gap adjacent to the groove. 
     
     
       11. The apparatus defined in  claim 10  wherein the printed circuit comprises a flexible printed circuit. 
     
     
       12. The apparatus defined in  claim 11  wherein the electrical component comprises an integrated circuit and wherein the ceramic substrate has a rectangular opening. 
     
     
       13. The apparatus defined in  claim 7 , further comprising an additional surface that couples the outer-most edge surface to the surface of the groove, wherein the additional surface is substantially perpendicular to the outer-most edge surface and the surface of the groove. 
     
     
       14. The apparatus defined in  claim 13 , wherein the metal coating additionally coats the additional surface and a portion of the outer-most edge surface. 
     
     
       15. The apparatus defined in  claim 14 , wherein the metal coating additionally coats a portion of the upper surface and a portion of the lower surface.

Description:
BACKGROUND 
     This relates generally to substrates on which electronic components in electronic devices are mounted, and, more particularly, to shielding such substrates to prevent electromagnetic interference. 
     Electronic devices include components such as sensors, integrated circuits, and other electrical components. These components are mounted on substrates. To prevent electromagnetic interference, substrates are sometimes shielded with metal shielding cans. In some situations, the entire edge of a printed circuit board substrate may be shielded by folding up a locally thinned portion of a flexible printed circuit that contains ground traces so that the ground traces cover the edge. 
     Shielding structures such as these may be unable to block electromagnetic interference from certain substrates, may consume more volume within a device than desired, and may be unreliable and difficult to manufacture. 
     It would therefore be desirable to be able to provide improved techniques for providing substrates and components mounted to the substrates with electromagnetic interference shielding. 
     SUMMARY 
     An electronic device may have electrical components such as integrated circuits and other components. An electrical component may be mounted on a substrate such as a ceramic substrate. The ceramic substrate may be used to mount the electrical component to a printed circuit such as a flexible printed circuit. 
     The ceramic substrate may have a rectangular central opening surrounded by a ring-shaped ceramic member. Contacts may be formed on the upper and lower surfaces of the substrate. The electrical component may be soldered to the contacts on the upper surface. The contacts on the lower surface may be used to solder the substrate to mating contacts on the printed circuit. 
     During manufacturing, it may be desirable to use metal traces on a ceramic panel to make connections to contacts on the substrate. Following singulation of the ceramic panel to form the ceramic substrate, some of the metal traces may run to the edge of the ceramic substrate. A folded tab of the printed circuit may form a shield that covers these exposed traces. Along other portions of the edges of the substrate, electromagnetic interference shielding may be formed from a metal-coated notch or a row of metal-coated vias. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device such as a handheld computing device that may be provided with electromagnetic interference shielding structures in accordance with an embodiment. 
         FIG. 2  is a schematic diagram of an illustrative electronic device that may be provided with electromagnetic interference shielding structures in accordance with an embodiment. 
         FIG. 3  is an exploded perspective view of an electrical component, a substrate to which the electrical component may be mounted, and a printed circuit to which the substrate may be mounted in accordance with an embodiment. 
         FIG. 4  is a perspective view of an illustrative electrical component mounted on a substrate that is mounted to a printed circuit in accordance with an embodiment. 
         FIG. 5  is a cross-sectional side view of an illustrative electronic component mounted to a substrate that is mounted to a printed circuit in accordance with an embodiment. 
         FIG. 6  is a perspective view of an edge portion of an illustrative substrate in accordance with an embodiment. 
         FIG. 7  is a cross-sectional side view of an edge portion of a substrate to which an electrical component has been soldered in accordance with an embodiment. 
         FIG. 8  is a top view of a portion of a sheet of substrate material showing how metal traces may be used to couple contacts on a substrate to external contact pads before the a substrate is cut out of the substrate material in accordance with an embodiment. 
         FIG. 9  is a perspective view of an edge portion of the substrate of  FIG. 8  after the substrate has been cut out of a sheet of substrate material in accordance with an embodiment. 
         FIG. 10  is a top view of an illustrative sheet of substrate material that has been provided with grooves that run along the edges of a rectangular substrate to be cut from the sheet of material in accordance with an embodiment. 
         FIG. 11  is a bottom view of a sheet of substrate material with a groove that runs along the edge of a rectangular substrate to be cut from the sheet of material and having metal traces that are routed around the groove in accordance with an embodiment. 
         FIG. 12  is a perspective view of an edge portion of a substrate with edge shielding formed from a metallized groove that runs along the edge of the substrate in accordance with an embodiment. 
         FIG. 13  is a perspective view of an illustrative substrate that has been mounted to a flexible printed circuit having a foldable tab for providing a corner of the substrate with shielding in accordance with an embodiment. 
         FIG. 14  is a perspective view of an illustrative substrate that has been mounted to a flexible printed circuit with a foldable shielding tab that has been folded up to cover and shield a corner portion of the substrate in accordance with an embodiment. 
         FIG. 15  is a cross-sectional side view of an edge portion of an illustrative substrate being shielded by a folded shielding tab on a flexible printed circuit in accordance with an embodiment. 
         FIG. 16  is a top view of an illustrative substrate structure in which a row of metallized vias is used to provide edge shielding for a substrate in accordance with an embodiment. 
         FIG. 17  is a bottom view of the structure of  FIG. 16  showing how metal traces may be routed in the gaps between respective vias in a row of edge shielding vias for a substrate in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices may be provided with electrical components such as sensors, integrated circuits, light-emitting diodes and other components that emit light, light detectors, cameras, buttons, speakers, microphones, vibrators, tone generators, communications circuitry, and other electrical components. These components may be mounted on substrates such as ceramic substrates, printed circuits, plastic structures, and other substrate structures. In turn, the ceramic substrate to which an electrical component has been mounted may be attached to another substrate such as a printed circuit substrate. The printed circuit to which the ceramic substrate is mounted may be a rigid printed circuit (e.g., a printed circuit formed from fiberglass-filled epoxy or other rigid printed circuit board material) or a flexible printed circuit (e.g., a printed circuit formed from a sheet of polyimide or a layer of other flexible polymer). Electromagnetic interference shielding may be used to reduce electromagnetic interference in the components of an electronic device. For example, a substrate to which an electrical component such as an integrated circuit has been mounted may be provided with edge shielding structures that help block electromagnetic interference signals along the edges of the substrate. 
       FIG. 1  is a perspective view of an illustrative electronic device of the type that may contain electrical components mounted on substrates having electromagnetic interference shielding. An electronic device such as electronic device  10  of  FIG. 1  may be a computing device such as a laptop computer, a computer monitor containing an embedded computer, a tablet computer, a cellular telephone, a media player, or other handheld or portable electronic device, a smaller device such as a wrist-watch device, a pendant device, a headphone or earpiece device, or other wearable or miniature device, a television, a computer display that does not contain an embedded computer, a gaming device, a navigation device, an embedded system such as a system in which electronic equipment with a display is mounted in a kiosk or automobile, equipment that implements the functionality of two or more of these devices, or other electronic equipment. In the illustrative configuration of  FIG. 1 , device  10  is a portable device such as a cellular telephone, media player, tablet computer, or other portable computing device. Other configurations may be used for device  10  if desired. The example of  FIG. 1  is merely illustrative. 
     In the example of  FIG. 1 , device  10  includes a display such as display  14 . Display  14  has been mounted in a housing such as housing  12 . Housing  12 , which may sometimes be referred to as an enclosure or case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of any two or more of these materials. Housing  12  may be formed using a unibody configuration in which some or all of housing  12  is machined or molded as a single structure or may be formed using multiple structures (e.g., an internal frame structure, one or more structures that form exterior housing surfaces, etc.). 
     Display  14  may be a touch screen display that incorporates a layer of conductive capacitive touch sensor electrodes or other touch sensor components (e.g., resistive touch sensor components, acoustic touch sensor components, force-based touch sensor components, light-based touch sensor components, etc.) or may be a display that is not touch-sensitive. Capacitive touch screen electrodes may be formed from an array of indium tin oxide pads or other transparent conductive structures. 
     Display  14  may include an array of display pixels formed from liquid crystal display (LCD) components, an array of electrophoretic display pixels, an array of plasma display pixels, an array of organic light-emitting diode display pixels, an array of electrowetting display pixels, or display pixels based on other display technologies. 
     Display  14  may be protected using a display cover layer such as a layer of transparent glass or clear plastic. Openings may be formed in the display cover layer. For example, an opening may be formed in the display cover layer to accommodate a button such as button  16 . An opening may also be formed in the display cover layer to accommodate ports such as speaker port  18 . 
     A schematic diagram of device  10  is shown in  FIG. 2 . As shown in  FIG. 2 , electronic device  10  may include control circuitry such as storage and processing circuitry  40 . Storage and processing circuitry  40  may include one or more different types of storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory), volatile memory (e.g., static or dynamic random-access-memory), etc. Processing circuitry in storage and processing circuitry  40  may be used in controlling the operation of device  10 . The processing circuitry may be based on a processor such as a microprocessor and other suitable integrated circuits. With one suitable arrangement, storage and processing circuitry  40  may be used to run software on device  10  such as internet browsing applications, email applications, media playback applications, operating system functions, software for capturing and processing images, software implementing functions associated with gathering and processing sensor data, software that makes adjustments to display brightness and touch sensor functionality, etc. 
     Input-output circuitry  32  may be used to allow input to be supplied to device  10  from a user or external devices and to allow output to be provided from device  10  to the user or external devices. 
     Input-output circuitry  32  may include wired and wireless communications circuitry  34 . Communications circuitry  34  may include radio-frequency (RF) transceiver circuitry formed from one or more integrated circuits, power amplifier circuitry, low-noise input amplifiers, passive RF components, one or more antennas, and other circuitry for handling RF wireless signals. Wireless signals can also be sent using light (e.g., using infrared communications). 
     Input-output circuitry  32  may include input-output devices  36  such as button  16  of  FIG. 1 , joysticks, click wheels, scrolling wheels, a touch screen such as display  14  of  FIG. 1 , other touch sensors such as track pads or touch-sensor-based buttons, vibrators, audio components such as microphones and speakers, image capture devices such as a camera module having an image sensor and a corresponding lens system, keyboards, status-indicator lights, tone generators, key pads, and other equipment for gathering input from a user or other external source and/or generating output for a user. 
     Sensor circuitry such as sensors  38  of  FIG. 2  may include an ambient light sensor for gathering information on ambient light levels, proximity sensor components (e.g., light-based proximity sensors and/or proximity sensors based on other structures), accelerometers, gyroscopes, magnetic sensors, and other sensor structures. 
     Control circuitry  40  and input-output circuitry  32  may contain electrical components such as integrated circuits and other components that are mounted on substrates.  FIG. 3  is a perspective view of an illustrative component and associated mounting structures for device  10 . As shown in  FIG. 3 , device  10  may have one or more electrical components such as electrical component  42 . These electrical components may include one or more integrated circuits such as an image sensor integrated circuit, discrete components such as resistors, inductors, and capacitors, and other circuits. Components such as components  42  may be mounted to the upper and/or lower surfaces of substrate  44 . Substrate  44 , in turn, may be mounted on printed circuit  50 . 
     One or more of components  42  may have a rectangular shape. Substrate  44  may have a corresponding rectangular outline. If desired, the center of substrate  44  may be provided with an opening such as rectangular opening  46  to accommodate light for an image sensor, to help prevent damage to a mounted component in event of a drop event, etc.). 
     Substrate  44  may be formed from ceramic or other dielectric materials. Contacts  62  may be provided on the upper surface of substrate  44 . Contacts may also be provided on an opposing lower surface of substrate  44  (and, if desired, on a recessed ledge in substrate  44 ). With a configuration of the type shown in  FIG. 3  in which substrate  44  has a rectangular ring shape surrounding a central rectangular opening such as opening  46 , contacts  62  may include contacts that are arranged in a rectangular ring surrounding opening  46  (i.e., contacts  62  may run along each of the four edges of substrate  44 ). Contacts  62  may be formed from a conductive material such as metal. Vias may be used to couple contacts  62  to corresponding contacts on the underside of substrate  44 . The underside contacts of substrate  44  may be configured to mate with corresponding contacts  52  on the upper surface of an additional substrate such as printed circuit  50 . Contacts  52 , which may be formed from metal, may be coupled to the contacts on the underside of substrate  44  using solder or other conductive material. Printed circuit  50  may be a rigid printed circuit board, a flexible printed circuit, or other substrate material. As an example, printed circuit  50  may be a flexible printed circuit having two or more dielectric layers and patterned metal traces. If desired, one or more openings may be formed in printed circuit  50 . 
     When assembled, integrated circuit  42  is soldered or otherwise connected to the upper surface of substrate  44  and substrate  44  is soldered or otherwise connected to flexible printed circuit  50 , as shown in the perspective view of  FIG. 4 . Flexible printed circuit  50  may have a portion that is terminated in a connector on a main logic board or may otherwise have portions that are routed to desired locations within device  10 . 
     A cross-sectional side view of the structures of  FIG. 4  taken along line  54  and viewed in direction  56  is shown in  FIG. 5 . As shown in  FIG. 5 , component  42  may have contacts (terminals) such as contacts  58 . Substrate  44  may have an upper surface with contacts  62  and a lower surface with contacts  64 . Vias  70  may be used to electrically connect contacts  62  to respective contacts  64 . Vias  70  may be formed by machining, laser drilling, or other hole formation techniques. Vias  70  may be metallized. For example, electroplating techniques may be used to form metal coatings on the inner walls of the holes used to form vias  70 . Other hole formation and metal coating techniques may be used for forming vias  70 , if desired. Printed circuit  50  may contain layers of dielectric and patterned metal traces for forming signal paths. Contacts  52  on the upper surface of printed circuit  50  may mate with contacts  64  on the lower surface of substrate  44 . 
     Solder joints  60  may be used to couple contacts  58  on electrical component  42  to corresponding contacts  62  on substrate  44 . Solder joints  66  may be used to couple contacts  64  on the lower surface of substrate  44  to contacts  52  on the upper surface of printed circuit  50 . If desired, other conductive materials such as conductive adhesive may be used in mounting component  42  to substrate  44  and in mounting substrate  44  to printed circuit  50 . 
     A perspective view of an edge portion of substrate  44  is shown in  FIG. 6 . As shown in  FIG. 6 , contact  62  may have a portion that overlaps and electrically connects with metal in via  70 . The metal on the walls of via  70  may be used to connect contact  62  to a corresponding one of contacts  64  on the lower surface of substrate  44 . If desired, vias  70  may be filled with metal (i.e., the hole forming each via  70  may be completely filled with metal). The illustrative configuration of  FIG. 6  in which metal runs down the walls of via  70  is merely illustrative. 
       FIG. 7  is a cross-sectional side view of the structures of  FIG. 6  taken along line  74  and viewed in direction  76  in a configuration in which component  42  has been mounted on substrate  44 . As shown in  FIG. 7 , via  70  may be formed by metal coating  78  on the sidewalls of opening  80  in substrate  44 . Opening  80  may be a cylindrical hole running along vertical axis Z of  FIG. 7  or may be an opening with other suitable shapes. Sidewall metal coating  78  may be formed using electroplating (i.e., electrochemical deposition) or other suitable metal deposition techniques. Contact (solder pad)  62  is formed on upper surface  82  of substrate  44  and is connected to metal  78  of via  70 . Contact (solder pad)  64  is formed on opposing lower surface  84  of substrate  44  and is also connected to metal  78  of via  70  (i.e., upper surface contact  62  is shorted to lower surface contact  64  through via  70 ). If desired, the interconnect structures in substrate  44  may include paths that interconnect adjacent paths, paths that allow contacts to be distributed across one or both surfaces of substrate  44  in a desired path, or other interconnect patterns. The arrangement of  FIG. 7  is merely illustrative. 
     Substrates such as substrate  44  may be cut out of a large panel of substrate material. This allows some of the processing steps involved in forming substrate  44  to be consolidated and performed in an environment that is suitable for mass production. The process of cutting substrates  44  from a large panel of substrate material (i.e., cutting substrates  44  from a sheet of ceramic that is sufficiently large to be used in forming numerous individual ceramic substrates  44 ) is sometimes referred to as singulation. Singulation operations (dicing operations) may involve forming cuts through a ceramic panel using a saw or other cutting device. Openings such as opening  46  in the middle of each substrate  44  may, if desired, be formed during singulation operations. 
     It may be desirable to form electrical connections to the metal traces on substrate  44  such as contacts  62  and  64  and/or vias  70  prior to singulation (e.g., to facilitate electroplating, to perform continuity testing, etc.). Sacrificial metal traces may be used to form temporary signal paths. After contacts  62 ,  62 , and vias  70  have been successfully tested, unused portions of the metal traces be cut away (i.e., the substrate panel may be singulated to form individual substrates  44 ). The metal traces may be formed on upper surface  82  and/or lower surface  84  of substrate  44 . Configurations in which the metal traces are formed on lower surface  84  and are connected to contacts  64  are sometimes described herein as an example. This type of arrangement is, however, merely illustrative. Other types of metal trace patterns may be used if desired. 
       FIG. 8  is a bottom view of a portion of a ceramic panel prior to singulation to form substrate  44 . As shown in  FIG. 8 , metal traces  86  form integral portions of the metal traces on substrate  44  that are used in forming contacts  64 . Metal traces  86  include signal lines such as signal lines  88  and may include contacts such as test pads  90  to facilitate electroplating operations and continuity testing. During singulation, the ceramic panel may be sawn along saw lines such as saw line  94 , thereby forming left-hand edge  94  of substrate  44 . The panel may also be sawn along edges  96  (i.e., the right-hand edge, the upper edge, and the lower edge of substrate  44  in the orientation of  FIG. 8 ) to release substrate  44  from the panel. If desired, an opening such as opening  46  may also be formed in substrate  44  during singulation. 
     When sawing the ceramic, the saw (e.g., a mechanical saw, laser, or other cutting device) cuts through metal traces  86 . For example, lines  88  are cut in two (see, e.g., metal trace segment  88 ′, which is cut at location  98 ). This cutting process leaves small unused segments of metal traces  86  on substrate  44 , such as portion  100  of metal trace  88 ′ along each edge of substrate  44 . 
     A perspective view of an illustrative edge of substrate  44  following singulation is shown in  FIG. 9 . As shown in  FIG. 9 , unused segment  100  of path  88 ′ in sacrificial metal traces  86  remains on substrate  44  and is exposed along the bottom edge of outer wall  44 W of substrate  44 . 
     If traces such as trace  100  remain unshielded with metal shielding structures, it may be possible for electromagnetic interference signals to be emitted from substrate  44  during operation. These electromagnetic interference signals may interfere with the desired operation of device  10 . Accordingly, edge shielding structures may be formed along the edges of substrate  44 . The edge shielding structures may help prevent electromagnetic interference from leaking out of the metal traces on substrate  44 . 
     The edge shielding structures may be formed by creating grooves or other openings that run along the edges of substrate  44  and electroplating or otherwise depositing metal on the surfaces of the grooves or other openings, thereby forming vertically extending sidewall metal structures. The sidewall metal structures serve as edge shields that block electromagnetic interference. 
       FIG. 10  is a top view of a portion of a ceramic panel prior to singulation along line  44  to form a substrate. As shown in  FIG. 10 , four grooves may be formed in ceramic panel  102 . The surfaces of each groove (i.e., the sidewalls of each groove) may be electroplated or otherwise coated with metal. Groove  104 - 1  runs along the left-hand edge of substrate  44 , groove  104 - 2  runs along the upper edge of substrate  44 , groove  104 - 4  runs along the right-hand edge of substrate  44 , and groove  104 - 3  runs along the lower edge of substrate  44 . When substrate  44  is cut out of panel  102 , the metal that remains on the innermost edge of each groove will form a metal shielding structure that shields an associated portion of the edge of substrate  44 . 
     If desired, each groove may have one end that runs up to an associated corner of substrate  44  and another end that is recessed slightly from its nearest corner. The recessing of the end of each groove in this way provides a gap for signal lines associated with metal traces  86 .  FIG. 11  is a bottom view of an illustrative panel prior to singulation. As shown in  FIG. 11 , groove  104 - 3  may have a metal coating such as plated metal  108  that coats the walls of groove  104 - 3 . Grounded trace  110  may be used to ground the metal on groove  104 - 3  (if desired). 
     End  104 - 3 E of groove  104 - 3  is adjacent to corner  44 C 2  of substrate  44 . Opposing end  104 - 3 E of groove  104 - 3  is separated from opposing corner  44 C 1  of substrate  44  by gap  106 . Metal traces  86  may have segments  88 ′ that pass through gap  106 . Along the portion of the edge of substrate  44  that is covered by groove  104 - 3 , the metal on the inner surface of the groove will serve as an electromagnetic shield. Signal lines  88 ′ in gap  106  will not be shielded by the metal in groove  104 - 3 , but may be shielded by portions of a shield can, a bent tab of flexible printed circuit  50 , or other shielding structures. All four sides of substrate  44  may be shielded using structures of the type shown in  FIG. 11  or a subset of the sides of substrate  44  may be shielded using the configuration of  FIG. 11 . Shield can structures and other shielding structures may be used to enhance electromagnetic interference suppression. 
       FIG. 12  is a top perspective view of groove  104 - 3  of  FIG. 11  after singulating the ceramic panel to form substrate  44  of  FIG. 11 . As shown in  FIG. 12 , cut traces  88 ′ are present in gap  106  along the edge of substrate  44 . Metal coating  108  on the inner surface of groove  104 - 3  serves as electromagnetic interference shielding for the rest of the edge of substrate  44 . If desired, grooves such as groove  104 - 3  may have other shapes, may extend around one or more corners of device  10 , etc. Because groove  104 - 3  of  FIG. 12  has been split in two lengthwise along the edge of substrate  44 , metal-coated grooves such as groove  104 - 3  of  FIG. 12  are sometimes referred to as metal-coated split grooves, metal-coated half-grooves, or metal-coated divided grooves. 
     As shown in  FIG. 13 , printed circuit  50  may have a flexible protruding portion such as tab  50 T that can be folded upwards in direction  109  and attached over traces  88 ′ in gap  106  to shield traces  88 ′.  FIG. 14  shows the structures of  FIG. 14  following folding of tab  50 T upwards against substrate  44 . Conductive adhesive or other attachment structures may be used to hold tab  50 T in place. Only part of the edge of substrate  44  is preferably covered by tab  50 T, because groove shielding (see, e.g., metal  108  of groove  104 - 3  in  FIG. 12 ) provides shielding for the remainder of the edge. As tab  50 T extends only partway along the edge of substrate  44 , tab  50 T is easily folded upward against the edge of substrate  44  and does not exert excessive restoring force downwards following folding, enhancing reliability. 
     A cross-sectional side view of substrate  44  of  FIG. 14  taken along line  111  and viewed in direction  112  is shown in  FIG. 15 . As shown in  FIG. 15 , conductive adhesive  114  attaches tab  50 T of printed circuit  50  along the edge of substrate  44 . Tab  50 T may be thinner than other portions of printed circuit  50 . For example, main portion  50 M of printed circuit  50  may have layers such as a first patterned metal layer that forms contacts  52 , a first dielectric layer such as layer  118 , a second patterned metal layer such as metal layer  120  that forms signal line traces for distributing signals within main portion  50 M, and a second dielectric layer such as layer  122 . Main portion  50 M may also include other metal and dielectric layers, if desired. In tab  50 T, fewer layers of material may be included (i.e., the thickness of printed circuit  50  in tab region  50 T may be less than the thickness of printed circuit in main region  50 M under substrate  44 ). As an example, tab  50 T may include ground layer  116  that serves as an electromagnetic shielding layer covering all or most of tab  50 T and a dielectric substrate layer such as a layer  118 . The use of a thinned tab in printed circuit  50  may facilitate folding of tab  50 T against the side of substrate  44 . 
     If desired, edge shields can be formed using rows of plated vias.  FIG. 16  is a top view of an illustrative ceramic panel with a row of vias  130  that have been coated with metal  108  prior to singulation of substrate  44 .  FIG. 17  is a bottom view of the ceramic panel of  FIG. 16  prior to singulation (i.e., prior to splitting the vias along the edge of substrate  44  to form a row of metal-coated divided vias (sometimes referred to as half vias or split vias). As shown in  FIG. 17 , vias  130  may be plated with metal or otherwise coated with metal  108 . Gaps  132  may be formed between respective plated vias  130 , so that metal traces  88 ′ can protrude outwardly from contacts  64 . Following singulation, metal on vias  130  of  FIGS. 16 and 17  form edge shielding for substrate  44 . The spacing between vias is preferably less than a quarter wavelength or more preferably less than an eighth or tenth of a wavelength of the radio-frequency electromagnetic interference signals to be suppressed by the shielding. 
     If desired, substrate  44  may use multiple types of shielding. For example, part of the edges of substrate  44  may be shielded using groove-based shields formed from one or more metal-coated divided grooves extending along the edges of substrate  44 , part of the edges of substrate  44  may be shielded using shielding formed from a row of metal-coated divided vias running along the edges of substrate  44 , and part of the edges of substrate  44  may be shielded by folded flexible printed circuit portions (e.g., a folded tab such as tab  50 T that is an integral portion of a printed circuit such as a flexible printed circuit or that is a flexible printed circuit tail portion extending outward from a rigid printed circuit board portion in a “rigid flex” printed circuit, etc.). Shielding may also be provided using metal shielding can structures. 
     The foregoing is merely illustrative and various modifications can be made by those skilled in the art without departing from the scope and spirit of the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20140318
Publication Date: 20170228
Grant Date: 20170228
Priority Date: 20140318
Inventors: DINH RICHARD H.
SHUKLA ASHUTOSH Y.
MYERS SCOTT A.
Assignee: APPLE INC
CPC Classifications: [{"code": "H01L2924/014", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/15159", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/12044", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L24/81", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L24/13", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/81801", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/12041", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/15151", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/053", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/0401", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L23/49805", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L2224/16238", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/14", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K1/0218", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K2201/09354", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/15162", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/15787", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L23/49827", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K3/0052", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/12042", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L27/14618", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L23/552", "inventive": true, "first": true, "tree": "[]"}, {"code": "H05K2201/10378", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/131", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K3/363", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/16235", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L23/49838", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L2924/15311", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/16225", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/09618", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K1/189", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/09509", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/09145", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/2018", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L23/13", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L24/16", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L23/15", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/056", "inventive": false, "first": false, "tree": "[]"}, {"code": "H10F39/804", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K2201/2018", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/10378", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/09618", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/09509", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/09354", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/09145", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/053", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K3/363", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K3/0052", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K1/0218", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L23/49838", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L23/49827", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L23/49805", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L2924/12041", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/12044", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/12042", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/15787", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/15162", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/15159", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/15151", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/14", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/81801", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/16238", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/16235", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/131", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/0401", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L24/81", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L24/16", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L24/13", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L23/15", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L23/13", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/15311", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/16225", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/056", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K1/189", "inventive": false, "first": false, "tree": "[]"}, {"code": "H10F39/804", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K2201/056", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K1/189", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/2018", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/10378", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/09618", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/09509", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/09354", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/09145", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/053", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K3/363", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K3/0052", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K1/0218", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L23/49838", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L23/49827", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L23/49805", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L2924/12041", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/12044", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/12042", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/15787", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/15162", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/15159", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/15151", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/14", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/81801", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/16238", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/16235", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/131", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/0401", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L24/81", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L24/16", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L24/13", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L23/15", "inventive": false, "first":
Family ID: 54142840