Patent Publication Number: US-2021178518-A1

Title: Hermetic assembly and device including same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 62/947,924, filed Dec. 13, 2019, the disclosure of which is incorporated by reference herein in its entirety. 
    
    
     TECHNICAL FIELD 
     This disclosure generally relates to hermetic assemblies that include a ferrule and devices that include such assemblies. 
     BACKGROUND 
     Various systems require a hermetic seal between a window and a housing. Oftentimes, the window may include dielectric materials while the housing may include metallic metals. Such devices may include a sensor or port that requires that the window be transmissive to electromagnetic radiation for emission or detection or for viewing one or more components that are disposed within the housing. 
     Further, other systems may require electrical coupling between electrical devices disposed within a hermetically sealed enclosure and external devices. Oftentimes, such electrical coupling needs to withstand various environmental factors such that a conductive pathway or pathways from the external surface to within the enclosure remains stable. For example, implantable medical devices (IMDs), e.g., cardiac pacemakers, defibrillators, neurostimulators, and drug pumps, which include electronic circuitry and battery elements, require an enclosure or housing to contain and hermetically seal these elements within a body of a patient. Many of these IMDs include one or more electrical feedthrough assemblies to provide electrical connections between the elements contained within the housing and components of the IMD external to the housing, for example, sensors and/or electrodes and/or lead wires mounted on an exterior surface of the housing, or electrical contacts housed within a connector header, which is mounted on the housing to provide coupling for one or more implantable leads. Such leads typically carry one or more electrodes and/or one or more other types of physiological sensors. 
     A feedthrough assembly typically includes one or more feedthrough pins that extend between an interior and an exterior of the housing through a ferrule. Each feedthrough pin is electrically isolated from the ferrule, and, for multipolar assemblies, from one another, by an insulator element, e.g., glass or ceramic, that is mounted within the ferrule and surrounds the feedthrough pin(s). Glass insulators are typically sealed directly to the pin(s) and to the ferrule, e.g., by heating the assembly to a temperature at which the glass wets the pin(s) and ferrule, while ceramic insulators are typically sealed to the pin(s) and to the ferrule by a braze joint. High temperatures are typically required to join corrosion-resistant conductive materials with corrosion-resistant insulative materials. 
     SUMMARY 
     The techniques of this disclosure generally relate to various embodiments of a hermetic assembly. The assembly includes a ferrule that includes a body and a flange that extends from the body. The flange is welded to a welding portion of a patterned layer disposed between the flange and a first major surface of a dielectric substrate of the assembly such that the ferrule is hermetically sealed to the dielectric substrate. The hermetic assembly can form a part of a hermetically-sealed package, where a housing of the package can be connected to the ferrule of the assembly. 
     In one example, aspects of this disclosure relate to a hermetic assembly that includes a dielectric substrate having a first major surface and a second major surface, a patterned layer connected to the first major surface of the dielectric substrate by a laser bond, and a ferrule having a body and a flange extending from the body. The flange is welded to a welding portion of the patterned layer that is disposed between the flange and the first major surface of the dielectric substrate such that the ferrule is hermetically sealed to the dielectric substrate. 
     In another example, aspects of this disclosure relate to a hermetically-sealed package that includes a housing and a hermetic assembly that forms a part of the housing. The hermetic assembly includes a dielectric substrate having a first major surface and a second major surface, a patterned layer connected to the first major surface of the dielectric substrate by a laser bond, and a ferrule having a body and a flange extending from the body. The flange is welded to a welding portion of the patterned layer that is disposed between the flange and the first major surface of the dielectric substrate such that the ferrule is hermetically sealed to the dielectric substrate. An edge of the body of the ferrule is connected to an edge of the housing. 
     In another example, aspects of this disclosure related to a method that includes laser bonding a patterned layer to a first major surface of a dielectric substrate, and welding a flange of a ferrule to a welding portion of the patterned layer such that the welding portion is between the flange and the first major surface of the dielectric substrate and the ferrule is hermetically sealed to the dielectric substrate. The flange extends from a body of the ferrule. 
     The details of one or more aspects of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the techniques described in this disclosure will be apparent from the description and drawings, and from the claims. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic cross-section view of one embodiment of a hermetic assembly. 
         FIG. 2  is a schematic top plan view of the hermetic assembly of  FIG. 1 . 
         FIG. 3  is a schematic cross-section view of a hermetically-sealed package that includes the hermetic assembly of  FIG. 1 . 
         FIG. 4  is a flowchart of one embodiment of a method of forming the hermetically-sealed package of  FIG. 3 . 
         FIG. 5  is a schematic side view of one embodiment of an implantable medical device. 
         FIG. 6  is a schematic cross-section view of a portion of a hermetically-sealed package of the implantable medical device of  FIG. 5 . 
         FIG. 7  is a schematic perspective cross-section view of the hermetically-sealed package of the implantable medical device of  FIG. 5 . 
         FIG. 8  is a schematic bottom perspective view of a hermetic assembly of the hermetically-sealed package of  FIG. 7 . 
         FIG. 9  is a schematic perspective view of another embodiment of an implantable medical device. 
         FIG. 10  is a schematic cross-section view of a portion of the implantable medical device of  FIG. 9 . 
         FIG. 11  is a schematic perspective view of another embodiment of an implantable medical device. 
         FIG. 12  is a schematic cross-section view of the implantable medical device of  FIG. 11 . 
         FIG. 13  is a schematic cross-section view of another embodiment of a hermetic assembly. 
         FIG. 14  is a schematic plan view of the hermetic assembly of  FIG. 13 . 
         FIG. 15  is a schematic cross-section view of another embodiment of a hermetically-sealed package. 
         FIG. 16  is a schematic side view of a portion of the hermetically-sealed package of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION 
     The techniques of this disclosure generally relate to various embodiments of a hermetic assembly. The assembly includes a ferrule that includes a body and a flange that extends from the body. As used herein, the term “ferrule” refers to an element or component that resides between two or more additional components to facilitate physical connection and/or provides structural support of the components in the assembly. The flange is welded to a welding portion of a patterned layer disposed between the flange and a first major surface of a dielectric substrate of the assembly such that the ferrule is hermetically sealed to the dielectric substrate. The hermetic assembly can form a part of a hermetically-sealed package, where a housing of the package can be connected to the ferrule of the assembly. 
     Some feedthrough assemblies include a dielectric substrate that is connected to a metal battery or housing. Bonding of a dielectric material to a metal material can, however, be challenging. Some techniques for performing such bonding require a bonding surface of the metal battery or housing be polished such that it is extremely smooth. Such smooth bonding surfaces have to be kept clean prior to bonding so that flat, smooth, clean surfaces are presented for bonding. 
     Other techniques for bonding dielectric and metal materials include bonding or brazing a weld ring to a dielectric wafer and then welding the metal housing or battery to the weld ring. These techniques, however, can still require that bonding surfaces of the dielectric wafer and the weld ring be polished such that they are extremely smooth. And while a brazed weld ring may not require the same level of surface preparation as is required for other types of bonding, brazing is a high-temperature process that can create stress in the materials and limit the process order as well as size, shape, and design of the assembly due to such thermal stresses. 
     One or more embodiments of the present disclosure provide a hermetic assembly that includes a ferrule having a flange that is welded to a patterned layer disposed on a major surface of a dielectric substrate. The ferrule can be connected to a housing or battery with minimal or no polishing or use of a weld ring. Further, the ferrule can allow for thinner housing sidewalls and provides more area on the dielectric substrate for electronic components as compared to assemblies that utilize weld rings or other attachment techniques. One or more embodiments of the present disclosure can further simplify attachment of a housing to the dielectric substrate of the hermetic assembly. Further, the ferrule can aid in protecting edges of the dielectric substrate and also isolate the substrate from some external loads that can damage the substrate. One or more embodiments of ferrules described herein may be bonded only to one side of the dielectric substrate without needing to be bonded to the other side of such substrate. Further, bonding of the ferrule to the substrate after components have been disposed on the substrate is possible as high process temperatures typically needed for brazing ferrules to substrates are not necessary. 
     The various embodiments of hermetic assemblies described herein can be included in hermetically-sealed packages that can be utilized for any suitable application. In one or more embodiments, the hermetically-sealed package can maintain the integrity of a conductive pathway that connects an external contact electrode or device to components disposed within the package while protecting enclosed electronic devices or circuitry from undesired external environmental factors. 
     The various embodiments of hermetic assemblies and hermetically-sealed packages that include such assemblies can be utilized with any suitable devices or systems, e.g., electronic systems used, e.g., in smartphones, tablets, laptop computers, construction equipment, underwater equipment, implantable medical devices, etc. 
       FIGS. 1-2  are various schematic views of one embodiment of a hermetic assembly  10 . In one or more embodiments, the hermetic assembly  10  can be a feedthrough assembly as it includes one or more feedthroughs  18  as is further described herein. The assembly  10  includes a dielectric substrate  12  having a first major surface  14  and a second major surface  16 , a feedthrough  18  disposed in the dielectric substrate, and a patterned layer  20  connected to the first major surface of the dielectric substrate. In one or more embodiments, the patterned layer  20  can be a patterned conductive layer. The assembly  10  further includes a ferrule  22  that has a body  24  and a flange  26  extending from the body. The ferrule  22  is connected to a welding portion  28  of the patterned conductive layer  20  that is disposed between the flange  26  and the first major surface  14  of the dielectric substrate  12  such that the ferrule is hermetically sealed to the dielectric substrate. 
     The dielectric substrate  12  can include any suitable material or materials. In one or more embodiments, the substrate  12  can include a dielectric material, e.g., at least one of glass, quartz, silica, sapphire, silicon carbide, diamond, or gallium nitride. Further, the substrate  12  can include at least one of a biocompatible material or one or more coatings or layers that can provide biocompatibility. 
     In one or more embodiments, the substrate  12  can be a transparent substrate. As used herein, the phrase “transparent substrate” refers to a substrate that can transmit a given percentage of electromagnetic radiation incident thereon during use of laser bonding techniques described herein to preferentially heat only a major surface of the substrate (e.g., first major surface  14  or second major surface  16  of substrate  12 ), and not an inner bulk of the substrate, thereby creating a bond that has a relatively greater strength than the bulk strength of the substrate. In one or more embodiments, the substrate  12  can be substantially transparent at a desired wavelength or range of wavelengths. As used herein, the phrase “substantially transparent” means that the substrate transmits greater than 50% of electromagnetic radiation incident on the substrate for a selected wavelength or range of wavelengths, assuming no reflection at the air-substrate boundaries. In one or more embodiments, the substrate  12  can be substantially transmissive to electromagnetic radiation having a wavelength of at least 200 nm. In one or more embodiments, the substrate  12  can be substantially transmissive to electromagnetic radiation having a wavelength of greater than 10,000 nm. In one or more embodiments, the substrate  12  can be substantially transmissive to electromagnetic radiation having a wavelength in a range of 200 nm to 10,000 nm. In one or more embodiments, the substrate  12  can be substantially transmissive to at least one of UV light, visible light, or IR light. 
     The substrate  12  can include any suitable dimensions, e.g., thicknesses. Further, the substrate  12  can take any suitable shape or shapes. The substrate  12  can be a single, unitary substrate or multiple substrates joined together using any suitable technique or techniques. 
     Disposed in the substrate  12  is the feedthrough  18 , which can include any suitable feedthrough or feedthroughs that provide an electrical connection between the first major surface  14  and the second major surface  16  of the substrate. In one or more embodiments, the assembly  10  can include an array of feedthroughs  18 . The hermetic assembly  10  can include any suitable number of feedthroughs, e.g., 1, 2, 3, 4, 5, 10, 20, or more feedthroughs. Each feedthrough  18  of the assembly  10  can be substantially identical in construction. In one or more embodiments, one or more feedthroughs can have characteristics that are different from one or more additional feedthroughs. The feedthrough  18  can include a via  30  disposed between the first major surface  14  and the second surface  16  of the substrate  12 . A conductive material  32  can be disposed in the via  30  to provide an electrical pathway between the first major surface  14  and the second major surface  16  of the substrate  12 . 
     The feedthrough  18  can also include an external contact  34 . In one or more embodiments, the external contact  34  can be a portion of the patterned conductive layer  20  that is disposed adjacent the first major surface  14  of the substrate  12 . As used herein, the term “adjacent the first major surface of the substrate” means that an element or component is disposed closer to the first major surface of the substrate than to the second major surface of the substrate. In one or more embodiments, the external contact  34  can be disposed on the first major surface  14  of the substrate  12 . The external contact  34  can be disposed over the via  30  adjacent the first major surface  14  of the substrate  12 . In one or more embodiments, the external contact  34  can be electrically connected to the conductive material  32  disposed in the via  30 . The external contact  34  can be hermetically sealed to the first major surface  14  of the substrate  12  using any suitable technique or techniques. 
     The via  30  of the feedthrough  18  can be any suitable dimensions and take any suitable shape. The size and shape of the via  30  is predicated on the thickness of the substrate  12  and the techniques utilized to provide the conductive material  32  that forms the electrical pathway between the first major surface  14  and the second major surface  16  of the substrate  12 . Exemplary shapes for the via  30  can include parallel surface walls and/or tapered surface walls. In one or more embodiments where the substrate  12  has a thickness of approximately 100 to 500 μm, a typical opening for the via  30  at the first major surface  14  of the substrate  12  can be no greater than 500 μm, or no greater than 250 μm, or no greater than 100 micrometers, or no greater than 80 micrometers, or no greater than 50 micrometers, or no greater than 10 micrometers. Of course, the diameter of the via  30  could be larger (or smaller) than the illustrated examples based on the substrate thickness and/or the techniques utilized to provide the conductive material that forms the electrical pathway. Any suitable technique or techniques can be utilized to form the via  30 , e.g., drilling, chemical etching, laser etching, etc. 
     The feedthrough  18  can also include the conductive material  32  disposed in the via  30  to provide a conductive pathway between the first major surface  14  and the second major surface  16  of substrate  12 . The conductive material  32  can include any suitable conductive material or conductive materials, e.g., copper, titanium, aluminum, chromium, nickel, gold, platinum, composites (e.g., silver-filled epoxies), and combinations thereof. The conductive material  32  can be disposed in the via  30  using any suitable technique or techniques to provide a conductive pathway from external contact  34  to one or more devices or contacts disposed on or adjacent the second major surface  16  of the substrate  12 . In one or more embodiments, the conductive material  32  can be disposed in the via  30  such that it substantially fills the via. In one or more embodiments, the conductive material  32  can be disposed in the via along sidewalls of the via and the opening of the via at the first major surface  14 . 
     The feedthrough  18  can also include the external contact  34 . In one or more embodiments, the external contact  34  can be adapted to electrically couple the feedthrough  18  to a conductor or a contact of a device, e.g., a contact of a header of an implantable medical device. Such conductors and contacts can be electrically coupled to the external contact  34  using any suitable technique or techniques, e.g., soldering, physical contact, welding, etc. The external contact  34  can include any suitable conductive material or combination of conductive materials, e.g., at least one of copper, silver, titanium, niobium, zirconium, tantalum, stainless steel, platinum, iridium, aluminum, Kovar, or nickel (including clad structures, laminates etc.). In one or more embodiments, the external contact  34  can include two or more materials, e.g., bi-metals, clad laminates, etc. 
     Further, the external contact  34  can take any suitable shape or shapes. In one or more embodiments, the external contact  34  can take a circular shape in a plane parallel to the first major surface  14  of the substrate  12  as shown in  FIG. 2 . In one or more embodiments, the external contact  34  can take a rectangular shape in the plane parallel to the first major surface  14  of the substrate  12 . Further, the external contact  34  can take any suitable shape or shapes in a plane orthogonal to the first major surface  14  of the substrate  12 , e.g., square, tapered, domed, etc. In one or more embodiments, the external contact  34  can take substantially the same shape as an external contact of one or more additional feedthroughs  18 . In one or more embodiments, external contact  34  can take a shape that is different from the shape of an external contact of one or more additional feedthroughs  18 . Further, in one or more embodiments, one or more external contacts  34  can include complex shapes such as grooves or channels formed in the contact to facilitate attachment of conductors or electronic devices to the contacts. 
     The external contact  34  can also include any suitable dimensions. In one or more embodiments, the contact  34  can have any suitable thickness in a direction normal to the first major surface  14  of the substrate  12 . It is envisioned that for purposes of this disclosure, the dimension of the external contact&#39;s thickness is limited only by the fabrication techniques. With that in mind, in one or more example embodiments, a typical thickness can be at least 2 micrometers. In other example embodiments, it may be desirable to have the thickness be less than 10 millimeters, although greater thicknesses are also contemplated in accordance with embodiments of the disclosure. The thickness of the contact  34  can be the same as or different from the thickness of an external contact of one or more additional feedthroughs. In one or more embodiments, the external contact  34  can be of sufficient size and thickness to enable laser, resistance, or other welding and joining techniques to be utilized to electrically couple conductors and/or electronic devices to the external contact. 
     In one or more embodiments, the external contact  34  can be formed or disposed over the via  30  on the first major surface  14  of the substrate  12 . For purposes of the present disclosure, the terms “form,” “forming,” and “formed” will be used interchangeably with the terms “dispose,” “disposing,” and “disposed” respectively, such that the terms are considered to be equivalent. In other words, the external contact  34  is disposed over the via  30  such that the contact covers the via and the via is not visible in a plan view of the first major surface  14  of the substrate  12 . In one or more embodiments, the external contact  34  (or any of the external contacts described herein) can be formed separately from the substrate  12  as a discrete member, or it could be patterned from a conductive sheet or foil. 
     The external contact  34  is electrically coupled to the conductive material  32  that is disposed in the via  30 . In one or more embodiments, the external contact  34  is in direct contact with the conductive material  32  to electrically couple the contact to the conductive material. In one or more embodiments, one or more additional conductive layers (e.g., interlayer  40 ) can be disposed between the external contact  34  and the conductive material  32  to electrically couple the external contact to the conductive material. 
     In one or more embodiments, the external contact  34  is hermetically sealed to the first major surface  14  of the substrate  12 . Any suitable technique or techniques can be utilized to hermetically seal the external contact  34  to the first major surface  14  of the substrate  12 . For example, in one or more embodiments, the external contact  34  can be hermetically sealed to the first major surface  14  of the substrate  12  by a bond  35  that surrounds the via  30  as shown in  FIG. 2 . Any suitable technique or techniques can be utilized to form this bond  35 . For example, in one or more embodiments, the bond  35  can be formed using a laser to provide a laser bond. By surrounding the via  30  with the bond  35  that hermetically seals the external contact  34  to the first major surface  14  of the substrate  12 , the via is also protected from the external environment. The electrical coupling between the external contact  34  and the conductive material  32  disposed in the via  30  is, therefore, protected, and the integrity of this electrical pathway from the first major surface  14  of the substrate to the second major surface  16  can be maintained. In one or more embodiments, the external contact  34  can also be attached to the first major surface  14  of the substrate  12  using bonds in addition to bond  35 . For example, in one or more embodiments, the external contact  34  can be attached to the first major surface  14  by bond  35  and one or more additional bonds between the external contact  34  and the first major surface, e.g., point bonds. 
     In one or more embodiments, the feedthrough  18  can include an internal contact  36  disposed adjacent the second major surface  16  of the substrate  12 . As used herein, the term “adjacent the second major surface of the substrate” means that an element or component is disposed closer to the second major surface than to the first major surface of the substrate. The internal contact  36  can include any suitable material or materials, e.g., the same materials utilized for the external contact  34  or others, and can be formed using any suitable technique or techniques such as sputtering, plating, evaporating, etc. Further, the internal contact  36  can take any suitable shape or shapes and have any suitable thickness in a direction normal to the second major surface  16  of the substrate  12 , e.g., the same shapes and thicknesses as described regarding the external contact  34 , or other thicknesses and shapes such as conductive traces. 
     The internal contact  36  is disposed over the via  30  on the second major surface  16  of the substrate  12 . The contact  36  can be electrically coupled to the conductive material  32  disposed in the via  30 . The arrangement  30  of the external contact  34 , the via  30  and the internal contact  36  facilitates creation of an electrical pathway between the external side adjacent to the first major surface  14  and the interior side adjacent to the second major surface  16 . In one or more embodiments, the internal contact  36  is hermetically sealed to the second major surface  16  of the substrate  12  using any suitable technique or techniques, e.g., by a bond (e.g., laser bond) that surrounds the via  30 . 
     Connected to the first major surface  14  of the dielectric substrate  12  is the patterned layer  20 . The patterned layer  20  can include any suitable conductive or nonconductive material or materials, e.g., at least one of copper, silver, titanium, niobium, zirconium, tantalum, stainless steel, platinum, iridium, aluminum, Kovar, or nickel. In the embodiment illustrated in  FIGS. 1-2 , the patterned layer  20  is a patterned conductive layer. In one or more embodiments, the patterned conductive layer  20  can include a foil or foils disposed using any suitable technique or techniques. The patterned conductive layer  20  can include any suitable layers or sublayers. 
     Further, the patterned conductive layer  20  can be disposed in any suitable pattern when connected to the first major surface  14  of the dielectric substrate  12 . In one or more embodiments, one or more portions of the patterned conductive layer  20  can form one or more external contact  34  of one or more vias  18  disposed in the dielectric substrate  12 . Further, the patterned conductive layer  20  can include one or more welding portions  28  that can be utilized to connect the ferrule  22  to the dielectric substrate  12  as is further described herein. 
     Any suitable technique or techniques can be utilized to dispose the patterned conductive layer  20  on or adjacent the first major surface  14  of the dielectric substrate  12 . For example, the patterned conductive layer  20  can be disposed on or adjacent the first major surface  14  utilizing one or more of photolithography, etching, plasma vapor deposition, chemical vapor deposition, electroplating, laser bonding, etc. In one or more embodiments, the patterned conductive layer  20  can be connected to the first major surface  14  by one or more laser bonds  59 . 
     In one or more embodiments, the assembly  10  can include a second patterned conductive layer  38  disposed on or adjacent the second major surface  16  of the dielectric substrate  12 . The second patterned conductive layer  38  can include any suitable patterned conductive layer, e.g., patterned conductive layer  20 . In one or more embodiments, one or more portions of the second patterned conductive layer  38  can provide one or more internal contact  36  of one or more feedthroughs  18 . The same design characteristics and possibilities described herein regarding the first patterned conductive layer  20  can be applied to the second patterned conductive layer  38 . 
     The patterned conductive layer  20  can include any suitable number of layers. For example, the patterned conductive layer  20  can include a conductive sublayer  60  and an interlayer  40  disposed between the conductive sublayer and the first major surface  14  of the dielectric substrate  12 . The interlayer  40  can include any suitable material or materials, e.g., titanium, niobium, tantalum, zirconium, and alloys thereof. Further, the interlayer  40  can have any suitable dimensions. In one or more embodiments, the interlayer  40  can have a thickness as measured in a direction orthogonal to the first major surface  14  of the dielectric substrate  12  of at least 50 nanometers and no greater than 10 micrometers. The interlayer  40  can be disposed between the conductive sublayer  60  and the first major surface  14  of the dielectric substrate  12  using any suitable technique or techniques, e.g., the same techniques described herein regarding the patterned conductive layer  20 . In one or more embodiments, the interlayer  40  and the conductive sublayer  60  can be disposed on the first major surface  14  of the substrate  12  and then patterned using any suitable technique or techniques. Further, the second patterned conductive layer  38  can include any suitable number of layers. Although not shown, the second patterned conductive layer  38  can include one or more conductive sublayers and interlayers disposed between the conductive sublayers and the second major surface  16  of the dielectric substrate  12 . Any suitable interlayer or interlayers can be utilized, e.g., interlayer  40 . 
     Connected to the dielectric substrate  12  is the ferrule  22 . The ferrule  22  can include any suitable material or materials, e.g., at least one of titanium, niobium, or stainless steel. In one or more embodiments, the ferrule  22  can include a conductive material. The ferrule  22  can take any suitable shape or shapes and have any suitable dimensions. 
     For example, as shown in  FIG. 2 , the ferrule  22  can have an elliptical shape in a plane parallel to the first major surface  14  of the substrate  12 . Further, the flange  26  can also take an elliptical shape in the plane parallel to the first major surface  14  of the substrate  12 . 
     The ferrule  22  includes the body  24  and the flange  26  that extends from the body. The flange  26  can be integral with the body  24  or manufactured separately and attached to the body using any suitable technique or techniques. The flange  26  can include the same material or materials utilized to form the body  24 . In one or more embodiments, the flange  26  and the body  24  can include different materials. 
     As mentioned herein, the ferrule  22  can be connected to the dielectric substrate  12  using any suitable technique or techniques. As illustrated in  FIG. 1 , the ferrule  22  is connected to the welding portion  28  of the patterned conductive layer  20  that is disposed between the flange  26  and the first major surface  14  of the dielectric substrate  12  such that the ferrule is hermetically sealed to the dielectric substrate. In one or more embodiments, the ferrule  22  can be connected to the second major surface  16  of the dielectric substrate  12 . Further, in one or more embodiments, the ferrule  22  can be connected to the first major surface  14  and the second major surface  16  of the dielectric substrate, e.g., the ferrule can include a second flange (not shown) that can be connected to the second major surface of the dielectric substrate. In one or more embodiments, a major surface  42  of the flange  26  contacts the welding portion  28  of the patterned conductive layer  20  when the ferrule  22  is connected to the welding portion. In one or more embodiments, the major surface  42  of the flange  26  is substantially parallel to the first major surface  14  of the dielectric substrate  12 . As used herein, the term “substantially parallel” means that an angle formed between the major surface  42  of the flange  26  and the first major surface  14  of the dielectric substrate  12  is less than  10  degrees. Further, a gap between the major surface  42  of the flange  26  and the first major surface  14  of the dielectric substrate  12  is compatible with the joining techniques utilized to connect the flange to the dielectric substrate. 
     The flange  26  can be welded to the welding portion  28  of the patterned conductive layer  20  using suitable technique or techniques. In one or more embodiments, the flange  26  is welded to the welding portion  28  of the patterned conductive layer  20  by a weld  44 . Any suitable welding technique or techniques can be utilized to provide the weld  44 , e.g., laser welding. Further, the weld  44  can take any suitable shape or shapes and have any suitable dimensions. 
     In one or more embodiments, the ferrule  22  can be electrically connected to the patterned conductive layer  20  using any suitable technique or techniques. As shown in  FIG. 1 , the assembly  10  includes a second feedthrough  46  disposed in the dielectric substrate  12  that is electrically connected to the flange  26  of the ferrule  22 . The feedthrough  46  can include any suitable feedthrough, e.g., feedthrough  18 . The feedthrough  46  includes a via  48  disposed between the first major surface  14  and the second major surface  16  of the dielectric substrate  12 , and conductive material  50  disposed in the via. The conductive material  50  is electrically connected to the welding portion  28  of the patterned conductive layer  20  through the interlayer  40  if present. The welding portion  28  of the patterned conductive layer  20  is electrically connected to the flange  26  of the ferrule  22 . The second feedthrough  46  also includes an internal contact  52  disposed adjacent the second major surface  16  of the dielectric substrate  12  and electrically connected to the conductive material  50  disposed in the via  48 . As a result, the internal contact  52  is electrically connected to the ferrule  22 . 
     The assembly  10  can also include one or more electronics or electronic components  54  disposed adjacent at least one of the first major surface  14  or the second major surface  16  of the dielectric substrate  12 . The electronic component  54  can include any suitable circuit or component, e.g., at least one of a capacitor, transistor, integrated circuit, including controller or multiplexer, sensor, accelerometer, optical components such as emitters and detectors, etc. Although depicted as including one electronic component  54 , the assembly  10  can include any suitable number of electronic components. Further, the electronic component  54  can be electrically connected to one or more feedthroughs  18  using any suitable technique or techniques. In one or more embodiments, the electronic component  54  is electrically connected to one or more feedthroughs  18  by one or more device contacts  56 . Such device contacts  56  can be electrically connected to one or more internal contacts  36  of feedthroughs  18  using any suitable technique or techniques. In one or more embodiments, the electronic component  54  can include one or more test points (e.g., one or more test points  362  of  FIG. 8 ) disposed on one or surfaces of the electronic component as is further described herein. 
     As mentioned herein, one or more embodiments of assembly  10  can include the patterned conductive layer  20  that is connected (e.g., hermetically sealed) to the first major surface  14  of the dielectric substrate  12  using any suitable technique or techniques, e.g., welding, laser welding, laser bonding, diffusion bonding, laser-assisted diffusion bonding, etc. In one or more embodiments, the patterned conductive layer  20  can be connected to the first major surface  14  using the laser diffusion bonding techniques described in co-owned U.S. Pat. No. 10,124,559 B2, entitled KINETICALLY LIMITED NANO-SCALE DIFFUSION BOND STRUCTURES AND METHODS. For example, electromagnetic radiation (e.g., light) can be directed through the second major surface  16  of the dielectric substrate  12  and focused at an interface between the patterned conductive layer  20  and the first major surface  14  to form the laser bond  59  and laser bonds  35  of the external contacts  34 . In embodiments where the interlayer  40  is present, the electromagnetic radiation can be focused at an interface between the interlayer and the first major surface  14 . 
     Any suitable electromagnetic radiation can be utilized to form a bond between one or more portions of the patterned conductive layer  20  and the first major surface  14  of the dielectric substrate  12 . In one or more embodiments, the electromagnetic radiation can include laser light that can include any suitable wavelength or range of wavelengths. In one or more embodiments, the laser light can include light having a wavelength of at least 200 nm. In one or more embodiments, the laser light can include a wavelength of no greater than 10,000 nm. For example, laser light can include UV light, visible light, IR light, and combinations thereof. In one or more embodiments, a UV laser can be utilized to provide light having a wavelength of about 350 nm and a pulse width of 30 ns. In one or more embodiments, the materials for the substrate  12  and the patterned conductive layer  20 , and the power level and wavelength of the light used may be selected such that the light may not directly damage, ablate, warp, or cut the substrate and the patterned conductive layer, and such that the substrate and the patterned conductive layer retain their bulk properties. 
     In general, light can be provided by any suitable laser or laser system. For example, the laser may generate light having a relatively narrow set of wavelengths (e.g., a single wavelength). The light emitted by the laser may form a collimated beam that may not be focused at a particular point. The light emitted by the laser may be focused at interfaces between the patterned conductive layer  20  and the first major surface  14  to generate a laser bond. 
     Although the laser may provide light that has a narrow range of wavelengths, in one or more embodiments, the laser may represent one or more devices that emit light having a wider range of wavelengths than a single typical laser. A wide variety of devices may be used to emit light having a narrow or wide range of wavelengths. In one or more embodiments, the laser may include one or more laser devices including diode and fiber lasers. Laser sources may also include, e.g., TI sapphire, argon ion, Nd:YAG, XeF, HeNe, Dye, GaAs/AlGaAs, CO 2 , Alexandrite, InGaAs, InGaAsP, Nd:glass, Yb:YAG, or Yb fiber lasers. The laser device may also include one of continuous wave, modulated, or pulsed modes. Accordingly, a wide variety of laser devices may be used in the bonding process. In one or more embodiments, a power level of the laser may be set to approximately 1 W, distributed across the approximate focused beam diameter of 10 μm, with a top hat or Gaussian spatial energy profile. 
     As mentioned herein, the various embodiments of feedthrough assemblies can be utilized in any suitable device or system. For example,  FIG. 3  is a schematic cross-section view of one embodiment of a hermetically-sealed package  100 . The package  100  includes a housing  102  and the hermetic assembly  10  of  FIG. 1 . Although depicted as including the hermetic assembly  10  of  FIG. 1 , the hermetically-sealed package  100  can include any suitable hermetic assembly. In one or more embodiments, the hermetic assembly  10  can form a part of the housing  102 . The housing  102  defines a recess  112  within which one or more electronic components or circuitry (e.g., electronic component  54 ) can be disposed. Further, the housing  102 , ferrule  22 , and dielectric substrate  12  form a cavity  116 . 
     The housing  102  of the package  100  can include any suitable dimensions and take any suitable shape or shapes. In general, the housing  102  is sized and shaped to at least partially surround the electronic device  54 . In one or more embodiments, the housing  102  can include one or more sidewalls  104  that can be connected to the hermetic assembly  10  using any suitable technique or techniques as is further described herein. The housing  102  can completely surround and enclose the electronic device  54 , and the hermetic assembly  10  can be connected to the housing. In one or more embodiments, the housing  102  can include an open side or face, and the hermetic assembly  10  can be connected to the housing within this open side such that the hermetic assembly forms a part of the housing. The housing  102  can be a unitary housing or can include one or more sections that are joined together using any suitable technique or techniques. 
     The housing  102  can include any suitable material or materials, e.g., metal, polymeric, ceramic, or inorganic materials. In one or more embodiments, the housing  102  can include at least one of glass, quartz, silica, sapphire, silicon carbide, diamond, synthetic diamond, or gallium nitride (including clad structures, laminates etc.). In one or more embodiments, the housing  102  can include at least one of copper, silver, titanium, niobium, zirconium, tantalum, stainless steel, platinum, iridium, aluminum, nickel, Kovar, or AlMg (including clad structures, laminates etc.). In one or more embodiments, the housing  102  can include the same material or materials as the dielectric substrate  12  of the hermetic assembly  10 . 
     The package  100  can include any suitable electronic component  54  or electronics disposed within the housing  102 . In one or more embodiments, the electronic component  54  can include any suitable integrated circuit or device, e.g., a controller, a multiplexer, etc. It should be understood that any of the electronic devices mentioned in this disclosure can be coupled to a power source. Further, the package  100  can include a second electronic component  110  disposed in any suitable location within the housing  102 . The second electronic component  110  can include any suitable integrated circuit or device. In one or more embodiments, the second electronic component  110  can include a power source that is adapted to provide power to one or more integrated circuits or devices disposed within the housing  102  or exterior to the housing. Any suitable power source  110  can be disposed within the housing  102 , e.g., one or more batteries, capacitors, etc. The power source  110  can be rechargeable by electrically connecting the power source to a power supply through the hermetic assembly  10 . In one or more embodiments, the power source  110  can be adapted to be inductively charged by an inductive power system that is external to the package  100 . The power source  110  can be electrically connected to the electronic component  54  using any suitable technique or techniques. In one or more embodiments, the power source  110  can include a hermetically-sealed battery that is connected to the hermetic assembly  10  using any suitable technique or techniques. 
     The housing  102  can be connected to the hermetic assembly  10  using any suitable technique or techniques. In the embodiment illustrated in  FIG. 3 , an edge  58  of the body  26  of the ferrule  22  is connected to an edge  106  of the housing  102  by a bond or weld  108 . Any suitable technique or techniques can be utilized to form the weld  108 , e.g., the same techniques described herein regarding the weld  44  between the flange  24  and the welding portion  28  of the patterned conductive layer  20 . Further, the ferrule  22  can include an overhang  114  that is disposed adjacent the edge  106  of the housing  102 . In one or more embodiments, the overhang  114  can be adapted to block energy utilized to form weld  108  from damaging electronic component  54 . 
     As mentioned herein, the ferrule  22  of the hermetic assembly  10  can be electrically connected to the patterned conductive layer  20  via the welding portion  28  of the patterned conductive layer. As a result, the patterned conductive layer  20  can also be electrically connected to the housing  102  of the package  100  via the ferrule  22  and its connection to the housing. In one or more embodiments, the ferrule  22  can be electrically connected to a ground terminal that is, e.g., on the housing  102  of the package  100 . 
     The ferrule  22  of the assembly  10  can also include a slot  78  disposed in the body  26  of the ferrule. In one or more embodiments, the slot  78  can extend along the edge  58  and overhang  114  of the body  26  of the ferrule. The slot  78  can take any suitable shape or shapes and have any suitable dimensions. When the assembly  10  and the housing  102  are connected together, the slot  78  can be adapted to form a vent  80  with the edge  106  of the housing. In one or more embodiments, the slot  78  can be adapted to form the vent  80  with the edge  106  and the sidewalls  104  of the housing  102 . The vent  80  can allow backfill gas exchange of the package  100  before the assembly  10  is sealed to the housing  102 . Once gas exchange is completed, the vent  80  can be sealed with weld  108 . 
     For example,  FIG. 15  is a schematic plan view of an outer portion of the package  100 . As can be seen in  FIG. 15 , a substantial portion of the edge  58  of the body  26  of the ferrule  22  is connected to the edge  106  of the housing  102  by the weld  108 . A portion of the edges  58 ,  106  are, however, left unwelded such that the vent  80  is exposed. Gas exchange of the package  100  through the vent  80  can be performed. After gas exchange has been completed, the weld  122  can be completed over the remainder of edges  58 ,  106  and the vent  80  to seal the ferrule  22  to the housing  102 . 
     In one or more embodiments, the package  100  can include an optional second housing  118  connected to a second edge  120  of the body  26  of the ferrule  22 . All of the design considerations and possibilities regarding the housing  102  apply equally to the second housing  118 . The second housing  118  can be any suitable structure or component to which the assembly  10  is connected. In one or more embodiments, the second housing  118  can include a header of an implantable medical device (e.g., header  330  of  FIGS. 5-8 ). The second housing  118  can include the same materials as the housing  102  or different materials. 
     The second housing  118  can be connected to the second edge  120  of the ferrule  22  using any suitable technique or techniques, e.g., the same techniques described herein regarding the connection of the housing  102  to the ferrule. In one or more embodiments, the second housing  118  can be connected to the ferrule  22  by a weld  122  that is disposed through the second housing and into the ferrule. Further, the second edge  120  of the ferrule  22  can include a second overhang  124  that is disposed adjacent an edge  126  of the second housing  118 . 
     The second housing  118  can be electrically connected to the ferrule  22  using any suitable technique or techniques. In one or more embodiments, the second housing  118  can be electrically connected to the hermetic assembly  10  through the electrical connection of the ferrule  22  to the patterned conductive layer  20 . Further, the second housing  118  can be electrically connected to the housing  102  via the ferrule  22 . 
     The package  100  can be manufactured using any suitable technique or techniques. For example,  FIG. 4  is a flowchart of one embodiment of a method  200  of forming the hermetically-sealed package  100 . Although described in regard to the package  100 , the method  200  can be utilized to form any suitable hermetically-sealed package. 
     Method  200  includes disposing the power source  110  within the recess  112  of the housing  102  at  202 . In one or more embodiments, the power source  110  can be a hermetically-sealed battery that has been formed within housing  102  using any suitable technique or techniques. The patterned conductive layer  20  can be laser bonded to the first major surface  14  of the dielectric substrate  12  at  204 . Further, at  206 , the electronic device  54  can be disposed on the second major surface  16  of the dielectric substrate  12 . At  208 , the flange  26  of the ferrule  22  can be welded to the welding portion  28  of the patterned conductive layer  20  such that the welding portion is between the flange and the first major surface  14  of the dielectric substrate  12  and the ferrule is hermetically sealed to the dielectric substrate. Further, the edge  58  of the body  26  of the ferrule  22  can be connected to the edge  106  of the housing  102  (or hermetically-sealed battery) at  210  using any suitable technique or techniques such that the electronic device  54  is disposed within cavity  116 . In one or more embodiments, the weld  108  can be formed between the ferrule  22  and the housing  102  using any suitable technique or techniques. In one or more embodiments, the weld  108  hermetically-seals the assembly  10  to the housing  102 . 
     When the ferrule  22  includes the slot  78 , a portion of the edges  58 ,  106  can remain disconnected such that the vent  80  is exposed. In such embodiments, the method  200  can include a gas exchange between the package  100  and the environment external to the package. Any suitable gas exchange technique or techniques can be utilized. In one or more embodiments, a vacuum can be applied to the package  100  such that any internal gases or ambient air can be removed from the package. Optionally, the package  100  can be subjected to heat while under vacuum to remove any moisture from within the package. In one or more embodiments, the package  100  can be backfilled by exposing the package to an inert or low-reactive gas such as argon, nitrogen, helium, or combinations thereof, such that the gas enters the package through the vent  80 . While still in an inert gas environment, the weld  108  can be disposed over the vent  80  and between the remainder of the edge  58  of the body  26  of the ferrule  22  and the edge  106  of the housing  102  such that the assembly  10  is hermetically sealed to the housing. 
     In embodiments where the hermetically-sealed package  100  includes second housing  118 , the edge  126  of such housing can be connected to the second edge  120  of the body  26  of the ferrule  22  at  212  using any suitable technique or techniques. In one or more embodiments, the weld  122  can be formed through the edge  126  of the second housing  118  and into the second edge  120  of the body  26  of the ferrule  22 . In one or more embodiments where the second housing  118  is a header (e.g., header  308  of  FIGS. 5-8 ), the header can be connected to the second edge  120  of the body  26  of the ferrule  22  such that the header is electrically connected to the feedthrough  20  of hermetic assembly  10  using any suitable technique or techniques. In one or more embodiments, the gas exchange through vent  80  can occur prior to or after the second housing  118  is connected to the second edge  120  of the body  26  of the ferrule  22 . 
     The various embodiments of feedthrough assemblies described herein can be utilized with any device or system that requires hermetically sealed conductive pathways. For example, one or more embodiments of feedthrough assemblies described herein can be utilized with an implantable medical device or system. In one or more embodiments, the implantable medical device or system can employ one or more leads that may be used with the various embodiments of feedthrough assemblies described herein. Representative examples of such implantable medical devices include hearing implants, e.g., cochlear implants; sensing or monitoring devices; signal generators such as cardiac pacemakers or defibrillators, neurostimulators (such as spinal cord stimulators, brain or deep brain stimulators, peripheral nerve stimulators, vagal nerve stimulators, occipital nerve stimulators, subcutaneous stimulators, etc.), gastric stimulators; or the like. Further, in one or more embodiments, an implantable medical device can include one or more external contacts of a hermetic assembly that can be utilized to directly provide energy to tissue of a patient. 
     For example,  FIGS. 5-8  are various schematic views of one embodiment of an implantable medical device system  300 . The system  300  includes an implantable medical device (IMD)  302 , a lead  304 , and a lead extension  306 . 
     The IMD  302  includes a hermetically-sealed package  303  that includes a housing  310 , a hermetic (e.g., feedthrough) assembly  312  that forms a part of the housing, and a header  308  adapted to receive a proximal portion  314  of the lead extension  306 . All of the design considerations and possibilities regarding the hermetically-sealed package  100  of  FIG. 3  apply equally to the hermetically-sealed package  303  of IMD  302 . Although depicted as include a single hermetic assembly  312 , the IMD  302  can include any suitable number of hermetic assemblies. 
     The proximal portion  314  of lead extension  306  includes one or more electrical contacts  316  that are electrically connected to internal contacts (not shown) at distal connector  318  of the lead extension. The header  308  of the IMD  302  includes internal contacts  320  ( FIGS. 6-7 ) and is adapted to receive the proximal portion  314  of the lead extension  306  such that the internal contacts of the header may be electrically connected to the contacts  316  of the lead extension when the lead extension is inserted into the header. 
     The system  300  depicted in  FIGS. 5-8  further includes lead  304 . The depicted lead  304  has a proximal portion  322  that includes contacts  324  and a distal portion  326  that includes electrodes  328 . Each of the electrodes  328  can be electrically connected to a discrete contact  324 . The distal connector  318  of the lead extension  306  is adapted to receive the proximal portion  322  of the lead  304  such that the contacts  324  of the lead can be electrically connected to the internal contacts of the connector of the extension. Accordingly, a signal generated by the IMD  302  can be transmitted to tissue of a patient by an electrode  328  of lead  304  when the lead is connected to the extension  306  and the extension is connected to the IMD. In one or more embodiments, a signal received by electrode  328  of lead  304  from the patient may be transmitted to a contact  320  of the IMD  302  when the lead is connected to the extension  306  and the extension is connected to the IMD. 
     It will be understood that lead  304  can be connected to IMD  302  without use of an extension  306 . Any number of leads  304  or extensions  306  can be connected to device  302 . While lead  304  is depicted as having four electrodes  328 , it will be understood that the lead can include any number of electrodes, e.g. 1, 2, 3, 4, 5, 6, 7, 8, 16, 32, or 64 electrodes. Corresponding changes in the number of contacts  324  in lead  304 , contacts  316  and internal contacts in connector  318  of lead extension  306 , or internal contacts  320  in header  308  of device  302  may be required or desired. As used hereinafter, “lead” will refer to both “leads” and “lead extensions” unless the content and context clearly dictates otherwise. 
     The IMD  302  further includes the hermetically sealed package  303  in which electronics  334  are disposed. The housing  310  of the hermetically-sealed package  303  can include any suitable material or combination of materials, e.g., titanium, glass, sapphire, etc. In one or more embodiments, the housing  310  can be electrically conductive to provide a ground electrode for the IMD  302  as is known in the art. 
     Lead receptacles  330 ,  332  can be formed in the housing  336  of the header  308 . The receptacles  330 ,  332  can take any suitable shape or shapes and have any suitable dimensions. Although depicted as including two receptacles  330 ,  332 , the header  308  can include any suitable number or receptacles, e.g., 1, 2, 3, 4, or more receptacles. Further, the receptacles  330 ,  332  can be adapted to receive and electrically connect contacts  316  of the lead extension  306  (or contacts  324  of the lead  304 ) to contacts  320  of the header  308 . Any suitable number of leads  304  and lead extension  306  can be electrically connected to the header  308  via the receptacles  330 ,  332 . 
     The receptacles  330 ,  332  have internal contacts  320  positioned to align with and electrically connect with contacts  316  of the lead extension  306  and/or contacts  324  of the lead  304  when the lead extension or lead is properly inserted into one or both receptacles. The pitch of the internal contacts  320  of  FIG. 6  is adapted to allow electrical connection with the contacts  316  of the lead extension  306  or contacts  324  of the lead  304 . 
     Electronics  334  disposed within the package  303  are adapted to send electrical signals to tissue of the patient, or receive signals from tissue of the patient, through leads operably coupled to the electronics of the IMD  302 . As used herein, the term “transmitted electrical signals” is used to refer to both the signals sent by electronics  334  to tissue of the patient or received by the electronics from the tissue of the patient. In one or more embodiments, conductors of IMD  302  can be electrically connected to internal contacts  320  of lead receptacles  330 ,  332  via conductors  338  of hermetic assembly  312  that are electrically connected to a patterned conductive layer  340  of the assembly. For example, in one or more embodiments, conductors  338  can be electrically connected to the electronics  334  via a feedthrough that is disposed in a dielectric substrate  342  of the hermetic assembly  312 . In one or more embodiments, one or more conductors can be electrically connected to a patterned conductive layer disposed on a second major surface of the dielectric substrate  342  using any suitable technique or techniques. The feedthrough can include any suitable feedthrough described herein, e.g., feedthrough  18  of assembly  10  of  FIG. 1 . A conductive pathway is, therefore, formed between the internal contacts  320  of lead receptacles  330 ,  332  and electronics  334 . Hermetic assembly  312  can include any hermetic assembly described herein, e.g., hermetic assembly  10  of  FIGS. 1-3 . 
     In one or more embodiments, each conductor  338  can electrically connect an internal contact  320  of the lead receptacles  330 ,  332  to a discrete channel of the electronics  334 . As used herein, a “channel” of the electronics is a discrete electronic pathway through which signals may be transmitted independently of another channel. Each channel of the electronics  334  can be independently connected with a discrete internal contact  320  of the receptacles  330 ,  332 , which can be connected with a discrete contact  316  of the lead extension  306  or contact  324  of the lead  304 , which can in turn be connected with a discrete electrode  328  of the lead. Accordingly, each channel of the electronics  334  can be operably connected to a given electrode  328  of the lead  304 . 
     As shown in  FIG. 8 , one or more test points  362  can be disposed on a surface  335  of the electronics  334  (i.e., electronics package or component). such test points  362  can be utilized to test the electronics  334 . The test points  362  can be incorporated into the electronics  334  as part of a three-dimensional die stack of the electronics package. Although not shown, vertical interconnects such as vias can be disposed through one or more of the electronics  334  and electrically connected to the test points  362 . The surface  335  can be a non-functional surface such as glass with the test points  362  disposed on the surface and one or more vias disposed through the surface and into the layers of the electronics. In one or more embodiments, the surface  335  of the electronics  334  can be an active surface with the test points  362  disposed directly onto such active surface or on a redistribution layer disposed on the active surface. The test points  362  can be utilized to access schematic nodes disposed in a top layer or intermediate layers of the package of electronics  334  or to access schematic nodes disposed on the substrate  342  that are not disposed within the package. 
     Such placement of the test points  362  can reduce or eliminate the need for hybrid test points. Further, because the test points  362  are on or in the electronics stack, interconnections for such test points do not significantly increase the complexity of the stack. Further, such positioning of the test points  362  can reduce routing lengths to out-board test points, reduce EMI concerns, and simplify manufacturing. Further, the test points  362  can simplify burn-in when testing both in panel/wafer form and downstream when the devices are singulated. Also, troubleshooting completed devices can be simplified because the test points  362  remain formed on the electronics  334 . 
     As is also shown in  FIG. 8 , a ferrule  344  of the hermetic assembly  312  can include an optional slot  378 . The slot  378  can take any suitable shape or shapes and have any suitable dimensions. The slot  378  can be utilized to form a vent with the housing  336  to allow for gas exchange between the package  303  and the environment surrounding the package as is described herein regarding slot  78  and vent  80  of  FIG. 3 . 
     The hermetic assembly  312  can be disposed within the header  308  such that the housing  336  surrounds the assembly, and the assembly can be connected to a sidewall of the housing  310  of the IMD  302  between the header and the housing. In one or more embodiments, the hermetic assembly  312  can be disposed on any sidewall of the housing  310  such that the system does not include a header. In one or more embodiments, the hermetic assembly  312  can be connected to the housing by the ferrule  344  that is connected to a welding portion  346  of the patterned conductive layer  340  that is disposed between a flange  354  of the ferrule and a first major surface  348  of the dielectric substrate  342  such that the ferrule is hermetically sealed to the dielectric substrate. Any suitable technique or techniques can be utilized to hermetically seal the ferrule  344  to the dielectric substrate  342 , e.g., the same techniques described herein regarding the hermetically-sealed package  100  of  FIG. 3 . For example, the patterned conductive layer  340  can be connected to the first major surface  348  of the dielectric substrate  342  by a laser bond  356 . And the flange  354  of the ferrule  344  can be welded to the welding portion  346  of the patterned conductive layer  340  by weld  358  such that the ferrule is hermetically sealed to the dielectric substrate. Further, the hermetic assembly  312  can be disposed on a sidewall of the housing  310  using any suitable technique or techniques, e.g., the same techniques described herein regarding hermetically-sealed package  100  of  FIG. 3 . 
     The header  308  can be connected to at least one of the hermetic assembly  312  and the housing  310  using any suitable technique or techniques, e.g., the same techniques described herein regarding the hermetically-sealed package  100  of  FIG. 3 . In one or more embodiments, the hermetic assembly  312  can include tabs  350  ( FIG. 8 ) that can receive one or more fasteners that extend through openings in the header  308  and openings  352  in the tabs and connect the header to the hermetic assembly. Any suitable fasteners can be utilized to connect the header  308  to the hermetic assembly  312 . 
     As mentioned herein, the various embodiments of feedthrough assemblies described herein can be utilized in any suitable device. For example,  FIGS. 9-10  are various views of another embodiment of an implantable medical device  400 . All of the design considerations and possibilities regarding the implantable medical device  300  of  FIGS. 5-8  apply equally to the implantable medical device  400  of  FIGS. 9-10 . The device  400  includes a hermetically-sealed package  402  having a housing  404  and a hermetic (e.g., feedthrough) assembly  406  that forms a part of the housing. 
     The hermetic assembly  406  includes a dielectric substrate  410  and a ferrule  412 . The ferrule  412  includes a body  414  and a flange  416  extending from the body. The ferrule  412  is connected to a welding portion  418  of a patterned conductive layer  420  that is disposed between the flange  416  and a first major surface  422  of the dielectric substrate  410  such that the ferrule is hermetically sealed to the dielectric substrate. An edge  424  of the body  414  of the ferrule  412  is connected to an edge  426  of the housing  404 . 
     The hermetically-sealed package  406  also includes a second housing  408  that is connected to a second edge  428  of the body  414  of the ferrule  412 . Any suitable technique or techniques can be utilized to connect the second housing  408  to the ferrule  412 , e.g., the same techniques described herein regarding connection of the housing  102  and second housing  118  of the hermetically-sealed package  100  of  FIG. 3 . In one or more embodiments, the second housing  408  includes an external contact  430  that is adapted to provide an electrical signal to tissue of a patient using any suitable technique or techniques. In one or more embodiments, the external contact  430  can be electrically connected to the patterned conductive layer  420  of hermetic assembly  406  using any suitable technique or techniques. 
     The IMD  400  can take any suitable shape or shapes. In one or more embodiments, at least one of the housing  404 , second housing  408 , or the dielectric substrate  410  can have an elliptical cross-section in a plane that is substantially parallel to the first major surface  422  of the dielectric substrate  410 . Further, the IMD  400  can have any suitable dimensions. 
     The IMD  400  can further include one or more tines  432  that are connected to the second housing  408  using any suitable technique or techniques. In one or more embodiments, one or more of the tines  432  can be electrically connected to the hermetic assembly  406  using any suitable technique or techniques. 
       FIGS. 11-12  are various views of another embodiment of an implantable medical device (IMD)  500 . All of the design considerations regarding the implantable medical device  300  of  FIGS. 5-8  and the implantable medical device  400  of  FIGS. 9-10  apply equally to the implantable medical device  500  of  FIGS. 11-12 . The device  500  includes a hermetically-sealed package  502  having a housing  504  and a hermetic assembly  506  that forms a part of the housing. Although depicted as including a single hermetic assembly  506 , the implantable medical device  500  can include any suitable number of hermetic assemblies. 
     The hermetic assembly  506  includes a dielectric substrate  508  and a ferrule  510 . The ferrule  510  includes a body  512  and a flange  514  extending from the body. As can be seen in  FIG. 12 , the flange  516  extends from an upper portion  516  of the body  512 . The ferrule  510  is connected to a welding portion  518  of a patterned conductive layer  520  that is disposed between the flange  514  and a first major surface  522  of the dielectric substrate  508  such that the ferrule is hermetically sealed to the dielectric substrate. An edge  524  of the body  512  of the ferrule  510  is connected to an edge  526  of the housing  504  using any suitable technique or techniques, e.g., welding. 
     One difference between the IMD  500  of  FIGS. 11-12  and the IMD  400  of  FIGS. 9-10  is that the IMD  500  does not include a second housing. Instead, the hermetic assembly  506  forms the upper portion of the sealed package  502  of the IMD  500 . Further, the housing  504  connected to the ferrule  510  can be a sealed battery that is electrically connected to the hermetic assembly  506  using any suitable technique or techniques. 
     In one or more embodiments, the patterned conductive layer  520  can include an external electrode  528  disposed on the first major surface  522  of the dielectric substrate  508  as shown in  FIG. 11 . The external electrode  528  can be electrically connected to electronic component  530  that is connected to a second major surface  532  of the dielectric substrate  508  using any suitable technique or techniques. In one or more embodiments, the external electrode  528  can be adapted to direct energy (e.g., a signal) to tissue of a patient. In one or more embodiments, the external electrode  528  can be adapted to receive energy from tissue of the patient, thereby functioning as a sensor. In one or more embodiments, the external electric  528  can be adapted to direct and receive energy to and from tissue of a patient. 
     The IMD  500  can take any suitable shape or shapes. In one or more embodiments, at least one of the housing  504  or the dielectric substrate  508  can take a rectangular shape in a plane that is substantially parallel to the first major surface  522  of the dielectric substrate  508 . Further, the IMD  500  can have any suitable dimensions. 
     As described herein, the various embodiments of hermetic assemblies can be utilized in any suitable application. For example, one or more embodiments of hermetic assemblies can be utilized as an optical window or port that can provide a hermetically-sealed window for viewing of one or more components disposed within a housing connected to the assembly or for emission and detection of electromagnetic radiation that is directed through a dielectric substrate of the assembly. For example, an emitter that is adapted to emit electromagnetic radiation can be disposed within a housing that is in part formed by a hermetic assembly. Such electromagnetic radiation can be directed from within the housing and through a dielectric substrate that is hermetically sealed to a ferrule of the hermetic assembly. Such dielectric substrate, is, therefore, adapted to provide an optical window for the emitter. 
       FIGS. 13-14  are various view of one embodiment of a hermetic assembly  600 . All of the design considerations and possibilities regarding the hermetic assembly  10  of  FIGS. 1-2  and the hermetically-sealed package  100  of  FIG. 3  apply equally to the hermetic assembly  600  of  FIGS. 13-14 . 
     The hermetic assembly  600  includes a dielectric substrate  602  having a first major surface  604  and a second major surface  606 . The assembly  600  further includes a patterned layer  608  connected to the first major surface  604  of the dielectric substrate  602  by a laser bond  610 , and a ferrule  612  having a body  614  and a flange  616  extending from the body. The flange  616  is welded to a welding portion  618  of the patterned layer  608  that is disposed between the flange and the first major surface  604  of the dielectric substrate  602  such that the ferrule  612  is hermetically sealed to the dielectric substrate. 
     The hermetic assembly  600  can be connected to any suitable housing (e.g., housing  102  of package  100  of  FIG. 3 ) using any suitable technique or techniques. Further, the hermetic assembly  600  can be utilized with any suitable system or package, e.g., implantable medical device  500  of  FIGS. 11-12 . 
     The various embodiments of hermetically-sealed packages described herein can include any suitable number of hermetic assemblies. For example,  FIG. 15  is a schematic cross-section view of another embodiment of a hermetically-sealed package  700 . All of the design considerations and possibilities described herein regarding the hermetically-sealed package  100  of  FIG. 3  apply equally to hermetically-sealed package  700  of  FIG. 15 . The package  700  includes a first hermetic assembly  710  and a second hermetic assembly  770 . Each of the first and second hermetic assemblies  710 ,  770  can include any suitable hermetic assembly, e.g., hermetic assembly  10  of  FIGS. 1-2 . The package  700  can include identical assemblies  710 ,  770 . In one or more embodiments, the first assembly  710  is different from the second assembly  770 . Although depicted as including two hermetic assemblies  710 ,  770 , the package  700  can include any suitable number of assemblies. 
     The assemblies  710 ,  770  can be connected together using any suitable technique or techniques. In one or more embodiments, a ferrule  722  of the first assembly  710  is connected to a ferrule  772  of the second assembly  770 . In the embodiment illustrated in  FIG. 15 , an edge  758  of a body  726  of the ferrule  722  is connected to an edge  766  of a body  768  of the ferrule  772  by a bond or weld  764 . Any suitable technique or techniques can be utilized to form the weld  764 , e.g., the same techniques described herein regarding the weld  44  between the flange  26  and the welding portion  28  of the patterned conductive layer  20  of the assembly  10  of  FIGS. 1-2 . 
     The hermetic assemblies  710 ,  770  can form a part of a housing  702  of the package  700 . In such embodiments, additional portions of the housing  702  can be connected to one or both of the assemblies  710 ,  770  to form a hermetically-sealed enclosure  712 . In one or more embodiments, the assemblies  710 ,  770  form the entirety of the housing  702  and provide the hermetically-sealed enclosure  712 . 
     The package  700  can be utilized for any suitable device or system, e.g., an implantable medical device. The package  700  can provide such device sensing of electrical signals within a patient in two distinct directions. Further such device can provide more reliable telemetry with external transceivers as signals can be transmitted through one or both assemblies  710 ,  770 , which may be oriented in different directions. Also, the package  700  can be utilized with an implantable energy transfer system that can be adapted to receive electromagnetic energy through two or more sides of the housing  702  via the assemblies  710 ,  770 . 
     It should be understood that various aspects disclosed herein may be combined in different combinations than the combinations specifically presented in the description and accompanying drawings. It should also be understood that, depending on the example, certain acts or events of any of the processes or methods described herein may be performed in a different sequence, may be added, merged, or left out altogether (e.g., all described acts or events may not be necessary to carry out the techniques). In addition, while certain aspects of this disclosure are described as being performed by a single module or unit for purposes of clarity, it should be understood that the techniques of this disclosure may be performed by a combination of units or modules associated with, for example, a medical device. 
     In one or more examples, the described techniques may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored as one or more instructions or code on a computer-readable medium and executed by a hardware-based processing unit. Computer-readable media may include computer-readable storage media, which corresponds to a tangible medium such as data storage media (e.g., RAM, ROM, EEPROM, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer). 
     Instructions may be executed by one or more processors, such as one or more digital signal processors (DSPs), general purpose microprocessors, application specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuitry. Accordingly, the term “processor” as used herein may refer to any of the foregoing structure or any other physical structure suitable for implementation of the described techniques. Also, the techniques could be fully implemented in one or more circuits or logic elements.