Feedthrough assembly

Abstract

A feedthrough assembly comprising: a sleeve; an insulating structure; and a seal securely fixing the insulating structure within the sleeve, the seal comprising a glass and single phase particles dispersed therein; wherein the glass comprises: 25% to 40% B2O3; 0 to 25% CaO; 0 to 25% MgO; 0 to 25% SrO; 0 to 10% La2O3; 5% to 15% SiO2; and 10% to 20% Al2O3; wherein all percentages are in mole percent of the glass.

Description

Technical Field

[0001] This technology generally relates to feedthrough assemblies for use in implantable medical devices, and more specifically, to glass seals within feedthrough assemblies, wherein the glass seals comprise glass and single-phase particles dispersed therein. Background Technology

[0002] Many devices (e.g., implantable medical devices (IMDs)) and electrochemical cells (e.g., batteries, capacitors, or sensors) are hermetically sealed to prevent liquid contact with electronic components within the device. A typical feedthrough assembly includes a conductive element (e.g., a wire or pin), a sheath or sleeve member, an insulating member (e.g., glass, ceramic), and a seal. Feedthroughs include those described in U.S. Patent Nos. 6,855,456 and 5,175,067 to Taylor et al., and U.S. Patent Application Publication No. 2006 / 0247714. The sheath or sleeve member includes an orifice configured to receive the insulating member. A seal may be located between the sheath or sleeve member and the insulating member. The insulating member includes those formed of Ta-23 glass and Cabal-12 glass, as described in U.S. Patent No. 5,306,581 to Taylor et al. The exemplary feedthrough assembly can be inserted into, for example, a battery housing, such that a portion of the conductive element extends into the housing to connect with the battery element, while another portion of the conductive element extends outside the housing to connect with other electronic components.

[0003] There is a desire to develop improved feeders for IMD, particularly those that include insulating members made of a material that can be easily adjusted to have the mechanical properties required for the application. Summary of the Invention

[0004] This disclosure provides a feedthrough assembly comprising: a sleeve; an insulating structure; and a glass seal that securely holds the insulating structure within the sleeve, the glass seal (e.g., a first glass seal) comprising glass and single-phase particles dispersed therein (i.e., filler glass).

[0005] The glass (nominal) of the glass seal comprises: 25% to 40% B2O3; 0% to 25% CaO; 0% to 25% MgO; 0% to 25% SrO; 0% to 10% La2O3; 5% to 15% SiO2; and 10% to 20% Al2O3; wherein all percentages are molar percentages of the glass (and all component percentages total 100%).

[0006] In some embodiments, the single-phase particles of the glass seal comprise Al2O3, Y2O3, ZrO2, TiO2, MgO, ZnO, BaO, CaO, Nb2O5, Ta2O5, SiC, Si3N4, or mixtures thereof.

[0007] In some embodiments, the feedthrough assembly further includes at least one tail pin, wherein the insulating structure includes a top portion, a bottom portion, and an inner diameter portion, wherein the inner diameter portion defines at least one orifice extending from the top portion to the bottom portion, and wherein the at least one tail pin extends through the at least one orifice. In some embodiments, the feedthrough assembly further includes a gold solder that seals the at least one tail pin with the insulating structure. Alternatively, in some embodiments, the feedthrough assembly further includes a glass seal (e.g., a second glass seal) that seals the at least one tail pin with the insulating structure. In some embodiments, this second glass seal comprises the filler glass described herein.

[0008] In some embodiments, this disclosure provides a feedthrough assembly comprising: a sleeve; an insulating structure including a top portion, a bottom portion, and an inner diameter portion, wherein the inner diameter portion defines at least one orifice extending from the top portion to the bottom portion; at least one tail pin extending through the at least one orifice; and a glass seal that securely holds the at least one tail pin in place by the insulating structure. The glass seal comprises glass and single-phase particles dispersed therein; wherein the glass comprises 25% to 40% B₂O₃; 0 to 25% CaO; 0 to 25% MgO; 0 to 25% SrO; 0 to 10% La₂O₃; 5% to 15% SiO₂; and 10% to 20% Al₂O₃; wherein all percentages are molar percentages of the glass.

[0009] The term "comprising" and its variations, when used in the specification and claims, are not restrictive. Such terms should be understood to imply inclusion of the stated steps or elements or groups of steps or elements, but do not exclude any other steps or elements or groups of steps or elements. "Constitutes of" means to include and is limited to anything following the phrase "consisting of." Thus, the phrase "consisting of" indicates that the listed elements are necessary or required, and that no other elements can be present. "Substantially constitutes of" means to include any elements listed following the phrase, and is limited to other elements that do not interfere with or affect the activity or operation of the listed elements as defined in this disclosure. Thus, the phrase "substantially constitutes of" indicates that the listed elements are necessary or mandatory, but other elements are optional and may be present or absent depending on whether they substantially affect the activity or operation of the listed elements. Any element or combination of elements described in this specification in open-ended language (e.g., including and derived therefrom) is considered to be described in closed-ended language (e.g., constituting and derived therefrom) and partially closed-ended language (e.g., primarily constituting and derived therefrom).

[0010] The terms "preferred" and "ideally" refer to embodiments of this disclosure that may provide certain benefits in certain circumstances. However, other claims may also be preferred in the same or other circumstances. Furthermore, the recitation of one or more preferred claims does not imply that other claims are useless, nor is it intended to exclude other claims from the scope of this disclosure.

[0011] In this application, terms such as “a / an” and “the” are not intended to refer only to a singular entity, but rather to encompass general categories for which specific examples may be used for illustration. The terms “a / an” and “the” are used interchangeably with the term “at least one”. The phrases “at least one of” and “containing at least one of” following the list refer to any one of the items in the list and any combination of two or more items in the list.

[0012] As used herein, unless otherwise expressly indicated by the content, the term "or" is generally used in a meaning that includes "and / or".

[0013] The term “and / or” refers to one or all of the listed elements, or any combination of two or more of the listed elements.

[0014] Similarly, throughout this document, it is assumed that all numbers are modified by the term “about” and, in some embodiments, preferably by the term “exactly”. As used herein in conjunction with measured quantities, the term “about” refers to variations in the measured quantity as would be expected by a person skilled in the art who would perform the measurement and apply a level of care commensurate with the purpose of the measurement and the accuracy of the measuring equipment used. In this document, the number “at most” (e.g., at most 50) includes said quantity (e.g., 50).

[0015] Similarly, in this document, the description of an endpoint to a numerical range includes all numbers contained within the range as well as endpoints (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.) and any subranges (e.g., 1 to 5 includes 1 to 4, 1 to 3, 2 to 4, etc.).

[0016] The term "in the range" (and similar statements) includes the endpoints of the range being stated.

[0017] The grouping of alternative elements or embodiments disclosed herein should not be construed as limiting. Each group member may be mentioned and claimed individually or in any combination with other members in the group or other elements seen herein. It is contemplated that one or more members in a group may be included in or removed from the group for convenience and / or patentability reasons. When any such inclusion or removal occurs, this specification is considered to contain modified groups to satisfy the written description of all Markush groups as used in the appended claims.

[0018] Throughout this specification, references to "an embodiment," "an embodiment," "some embodiments," or "a number of embodiments," etc., mean that a particular feature, configuration, composition, or material or characteristic described in connection with that embodiment is included in at least one embodiment of this disclosure. Therefore, the appearance of such phrases throughout this specification does not necessarily refer to the same embodiment of this disclosure. Furthermore, in one or more embodiments, particular features, configurations, compositions, or characteristics may be combined in any suitable manner.

[0019] The above overview of this disclosure is not intended to describe every disclosed embodiment or every implementation of this disclosure. The following description illustrates illustrative embodiments in more specific terms. Guidance is provided in several places throughout this application by a list of examples that may be used in a variety of combinations. In each case, the listed examples are intended only as representative groups and should not be construed as exclusive. Any element positively described as an alternative in this specification may be expressly included in or excluded from the claims in any combination as desired. Although various theories and possible mechanisms may have been discussed herein, such discussion should in no way limit the scope of the claimable subject matter. Attached Figure Description

[0020] Exemplary embodiments will now be described more fully with reference to the accompanying drawings.

[0021] Figure 1 A schematic diagram of an implantable medical device is depicted;

[0022] Figure 2 This is a schematic cross-sectional view of a MEMS package including a feedthrough assembly;

[0023] Figure 3 and 4 These are respectively isometric views and cross-sectional views of a single-pole (single pin) feed assembly according to various embodiments of the present disclosure; and

[0024] Figures 5 to 7 A method for manufacturing an exemplary feedthrough assembly according to various embodiments of the present disclosure is shown. Detailed Implementation

[0025] This disclosure provides a feedthrough assembly for use in medical devices, such as in microelectromechanical systems (MEMS) packages. The conductive-sealed feedthrough connects an internal cavity within the MEMS device to another electronic component or device (e.g., a leaded interconnect) outside the MEMS package. Compared to packages employing epoxy attachments bonded to a silicon substrate, MEMS packages can be hermetically sealed and more separable from fluid-contact components.

[0026] Figure 1 A functional unit 20 in a medical device system 10 is depicted. The functional unit 20 is contained in or on an integrated circuit (IC) as a feedthrough assembly (not shown), a substrate containing electronic components (e.g., transistors, logic gates, switches), or a substrate only. The functional unit 20 can be used anywhere outside the medical device housing 12 and can be electrically connected to one or more conductors 18. For example, the functional unit 20 can be used as a sensor employing a feedthrough assembly (e.g., a pressure sensor).

[0027] The medical device system 10 includes a medical device housing 12 with a connector module 14 that electrically connects various internal electrical components of the medical device housing 12 to a proximal end 15a of a medical lead 16, such as one or more conductors 18 (e.g., coils, wires) extending to a distal end 15b of the lead 16. The medical device system 10 can include any wide variety of medical devices comprising one or more medical leads 16 and a circuitry connected to the medical leads 16. For example, the medical device system 10 can take the form of an implantable pacemaker that provides therapeutic stimulation to the heart or a neurostimulator. Alternatively, the medical device system 10 can take the form of an implantable cardioverter-defibrillator, an implantable pacemaker-cardioverter-defibrillator (PCD), an implantable pulse generator, or an implantable medical device that only monitors conditions associated with the patient.

[0028] Figure 2 A medical device system 10 is shown. Figure 1 One embodiment of the MEMS package 100. In one embodiment, the MEMS package 100 can be used in or for a sensor. For example, the MEMS package 100 can be associated with a converter that converts a signal into an electrical signal (i.e., voltage, current).

[0029] MEMS package 100 includes a feedthrough assembly 110, a first substrate 111, and a second substrate 128. The feedthrough assembly 110 is hermetically disposed in an aperture 106 of the first substrate 111 and coupled to the second substrate 128. The feedthrough assembly 110 (e.g., a glass-pin-insulator seal) includes a conductive element 112 (e.g., a pin) hermetically housed within an insulating member 114 (also referred to as a sealing glass or glass seal). The conductive element 112 may be formed of a conductive material such as tantalum (Ta), niobium (Nb), titanium (Ti), platinum (Pt), iridium (Ir), and / or alloys thereof.

[0030] The insulating member 114 may comprise glass. Typical glasses used to form the insulating member 114 include boron aluminum, boron aluminum silicate, and / or borosilicate type glasses, which have a wide range of thermal expansion to roughly match the material of the bio-stable conductive element 112, such as Ta, Nb, niobium titanium (Nb-Ti) alloys, Pt, Pt alloys, Ti, and alloys of Ti and / or other suitable materials. The elements and / or compounds used to form the insulating member 114 are selected in a manner that reduces the tensile stress on the conductive element 112. For example, the insulating member 114 using glass has a coefficient of thermal expansion (CTE) value equal to or within 15% of the CTE associated with the conductive element 110.

[0031] The insulating member 114 may be formed from a glass preform. For example, during the manufacture of the feedthrough assembly 110, the glass preform may be melted such that the molten glass joins the inner wall of the conductive element 112 and the orifice 106, and then cooled to form the insulating member 114.

[0032] The glass preforms (and resulting glass seals) described herein comprise a filler glass composition. The filler glass composition comprises glass and single-phase particles dispersed therein. There may be more than one glass seal, and therefore more than one filler glass composition. For example, references to a first glass seal, a first glass, or a first single-phase particle do not necessarily require the presence of a second glass seal, glass, or particles.

[0033] In some embodiments, the glass of the filled glass composition comprises 25% to 40% B2O3, 0 to 25% CaO, 0 to 25% MgO, 0 to 25% SrO, 0 to 10% La2O3 (preferably greater than 0%), 5% to 15% SiO2, and 10% to 20% Al2O3, wherein all percentages represent the molar percentage of the glass (and all component percentages total 100%).

[0034] In some embodiments, the glass of the filled glass composition comprises 30% to 40% B2O3, 0% to 20% CaO, 0% to 20% MgO, 0% to 20% SrO, 0% to 5% La2O3 (preferably greater than 0%), 5% to 10% SiO2 and 10% to 20% Al2O3, wherein all percentages represent the molar percentage of the glass (and all component percentages total 100%).

[0035] In some embodiments, the glass of the filled glass composition comprises at least one of CaO, MgO, or SrO. In some embodiments, the glass of the filled glass composition comprises a mixture of two or more of CaO, MgO, or SrO. In some embodiments, the glass of the filled glass composition comprises a mixture of CaO and MgO.

[0036] In some embodiments, the glass of the filled glass composition comprises 25% to 35% B2O3, 15% to 25% CaO, 15% to 25% MgO, 3% to 7% La2O3, 5% to 15% SiO2, and 10% to 20% Al2O3, wherein all percentages represent the molar percentage of the glass (and all component percentages total 100%).

[0037] In some embodiments, the glass of the filled glass composition contains up to 10% MnO2, and in some cases, the MnO2 content may be 15%.

[0038] In some embodiments, all or some of the CaO and / or MgO content is replaced by a corresponding amount of SrO. For example, 10% of CaO and 5% of MgO may be replaced by 15% SrO. However, the content of CaO and MgO is not completely replaced by SrO, and the total content of CaO, MgO, and SrO does not exceed 25% (or 20%).

[0039] In some embodiments, the glass comprises 30% to 50% of a component selected from the group consisting of CaO, MgO, and SrO and combinations thereof, provided that the content of each of CaO, MgO, and SrO does not exceed 25% (or 20%).

[0040] In some embodiments, the glass comprises 30% to 50% of a component selected from the group consisting of CaO, MgO, and combinations thereof, provided that the content of each of CaO and MgO does not exceed 25% (or 20%).

[0041] In some embodiments, the glass comprises 30% B2O3, 5% La2O3, 10% SiO2 and 15% Al2O3, and 30% to 50% of a component selected from the group consisting of CaO, MgO and combinations thereof, provided that the content of each of CaO and MgO does not exceed 25% (or 20%).

[0042] In some embodiments, the glass composition comprises 30% B2O3, 20% CaO, 20% MgO, 5% La2O3, 10% SiO2 and 15% Al2O3.

[0043] Glass materials can be manufactured using recognized techniques for forming glass.

[0044] The filled glass composition comprises single-phase particles. In this context, "single-phase" means a chemically homogeneous material consisting of two or more elements and having a characteristic crystalline structure.

[0045] Examples of single-phase particles include Al2O3, Y2O3, ZrO2, TiO2, MgO, ZnO, BaO, CaO, Nb2O5, Ta2O5, SiC, Si3N4, or mixtures thereof.

[0046] The type and amount of single-phase particles can be selected to provide desired physical properties without affecting the chemical properties of the glass. Examples of such physical properties include thermal expansion, modulus of elasticity, and fracture toughness. Depending on the selected particles and the amount used, these physical properties can be adjusted to meet application requirements.

[0047] For example, to achieve a robust seal in an electrically conductive circuit, the residual stress state of the seal must be carefully considered. To best utilize the filled glass described herein as a sealing material with niobium pins and titanium sleeves, it is desirable to reduce the glass's coefficient of thermal expansion (CTE). This can be achieved, for example, by adding alumina to the glass, as alumina has a lower CTE compared to glass. For instance, the CTE values ​​of alumina described herein and specific examples of glass (30% B₂O₃, 20% CaO, 20% MgO, 5% La₂O₃, 10% SiO₂, and 15% Al₂O₃) are 7.66 and 8.77 μm / m / ℃, respectively, from 25 °C to 630 °C. Due to the higher modulus of alumina, the elastic modulus of the glass increases with the addition of alumina.

[0048] Table 1 presents exemplary values ​​for the CTE and modulus of elasticity of a glass filled with alumina (30% B₂O₃, 20% CaO, 20% MgO, 5% La₂O₃, 10% SiO₂, and 15% Al₂O₃), with alumina added at a maximum of 25%. The properties reported in Table 1 were measured on a bulk shape made from a molten mixture of glass and alumina, which naturally contains a small amount of porosity. The CTE is generally independent of the small amount of porosity, while the modulus of elasticity is known to decrease with porosity. The porosity of the sample was 4.2%, which was only present in the glass portion of the seal; this porosity reduced the modulus of elasticity of the glass-alumina composite.

[0049] These modifications eliminate undesirable tensile stresses at the glass-pin interface in applications with alumina additions as low as 3 wt%. Seals with these filled glass compositions have been produced, exhibiting the desired robustness for titanium-based sleeves and niobium-based pins. The fracture resistance of the modified glass increases with increasing alumina load, which is highly desirable for improving the mechanical stability of the seal under pin loads. Specific embodiments of the glass described herein have a fracture toughness of 1.0 MPa-m. 0.5 And increased to 1.6 MPa-m 0.5 To add 10 wt% to 20 wt% of alumina to the glass.

[0050] Table 1

[0051]

[0052] In some embodiments, the average particle size of such single-phase particles is typically no more than 10 micrometers (i.e., microns). In some embodiments, the average particle size of such particles is typically no more than 5 micrometers. In some embodiments, the average particle size of such particles is typically at least 1 micrometer.

[0053] Single-phase particles can take any of a variety of shapes, but are not usually needle-shaped.

[0054] In some embodiments, the amount of single-phase particles is at least 1 wt% based on the total weight of glass and particles. In some embodiments, the amount of single-phase particles is at least 2 wt%, at least 3 wt%, at least 5 wt%, and at least 10 wt% based on the total weight of glass and particles. In some embodiments, the amount of single-phase particles is at most 25 wt% based on the total weight of glass and particles. In some embodiments, the amount of single-phase particles is at most 20 wt% based on the total weight of glass and particles. For example, in some embodiments, the amount of single-phase particles is 3 wt%, 5 wt%, 10 wt%, 13 wt%, 15 wt%, 16 wt%, or 20 wt% based on the total weight of glass and particles.

[0055] A variety of well-established techniques can be used to manufacture filled glass materials. For example, the glass material can be reduced to powder form by ball milling and then sieved to a suitable particle size for powder processing. Single-phase particulate powder (e.g., alumina powder) is available from various suppliers with high purity and is pre-sieved to a suitable particle size for mixing with the glass powder. Typically, desired amounts of glass and single-phase particulate (e.g., alumina) powder are blended and then thoroughly mixed in a ball mill. Bulk shapes can be formed by filling the mixed powder into a non-reactive tube (e.g., graphite) and then heating it in an inert gas (e.g., argon) to a temperature above the glass transition temperature. The glass powder is refluxing to form a continuous glassy matrix with minimal porosity and particle distribution throughout the glass. The refluxing temperature is set to ensure no reaction occurs between the particles and the glass. This general method can be extended to produce more complex shapes of filled glass, such as cylinders, for use as electrical feedthrough insulators.

[0056] The filled glass disclosed herein is not a glass-ceramic. In glass-ceramics, particles precipitate from the solution (as opposed to pre-formed particles premixed with glass powder). Therefore, the particles can be in needle-like form in glass-ceramics.

[0057] The various components of the filler glass composition are used in the manufacture of feedthrough assembly 110 ( Figure 2The presence of lanthanum oxide provides benefits and advantageous properties to the resulting insulating member 114. Specifically, La2O3 provides better glass flow during the melting and formation of the insulating member 114 because lower temperatures can be used compared to glass with little or no lanthanum oxide. Lanthanum oxide also increases the coefficient of thermal expansion (CTE) of the glass. For example, the CTE of glass with little or no lanthanum oxide can be 6.5, while the CTE of glass with lanthanum oxide as described herein can be 8.0. The increased CTE value is closer to that of metals such as niobium (Nb), titanium (Ti), platinum (Pt), iridium (Ir), and / or alloys thereof. After the feedthrough assembly 110 is formed and cooled, a similar change in CTE value occurs due to the compressive forces applied to the glass insulating member when it is placed within a sleeve (not shown) or the inner wall of the orifice 106. This change can result in excessive tensile forces, which can cause tensile cracking in the glass insulating member 114. The tendency for such tensile cracking can be reduced by using the composition of the present invention. For example, the composition of the present invention can provide a CTE value that is 10% to 15% smaller than the metal of the inner wall of the orifice 106 or the sleeve.

[0058] The presence of strontium oxide in the glass composition also lowers the processing temperature. For example, as described above, all or some amounts of CaO and / or MgO can be replaced by a corresponding amount of SrO. In this way, the processing temperature of the glass composition can be adjusted, for example, to offset the temperature necessary for processing the silica content.

[0059] In some embodiments, the composition of the present invention also limits the amount of SiO2 to no more than 15%, and in some embodiments to no more than 10%, because this amount provides long-term durability but does not substantially increase the processing temperature. For example, if SiO2 in the range of 20% or more, the temperature required for glass processing would increase to the point where titanium (which may be used, for example, in conductive element 112, as a sleeve portion, or in the first substrate 111) undergoes a phase transition. This could cause the titanium part, or other metal parts close to the melting temperature of the corresponding metal or alloy, to subsequently warp or deform. Therefore, the glass composition of the present invention keeps the silica content low to allow for lower processing temperatures at which the integrity of the titanium portion of the feedthrough assembly 110 can be maintained.

[0060] The glass-filled composition of the present invention also provides advantageous adhesion and sealing between the insulating member 114 and the inner wall of the orifice 106, and between the insulating member 114 and the conductive element 112. In other embodiments described below, the glass-filled composition provides adhesion and sealing to the sleeve. The glass-filled composition of the present invention can be used to replace glass insulating members used in feedthroughs, as described in: U.S. Patent Nos. 6,855,456, 5,306,581, 5,175,067, and 4,940,858 to Taylor et al., and U.S. Patent Application Publication No. 2006 / 0247714; and U.S. Patent No. 5,902,326 to Lessar et al.

[0061] The conductive element 112 and the first substrate 111 are hermetically bonded by an insulating material (e.g., glass) of the insulating member 114 that flows through and engages the inner wall of the conductive element 112 and the orifice 106. The hermetically sealed seal may match or substantially match the coefficient of thermal expansion (CTE) values ​​of all MEMS package components (e.g., within 10%). In another embodiment, the CTE may be within 5% for all MEMS package components. In another embodiment, the CTE may be within 2.5% for all MEMS package components. In yet another embodiment, the first substrate 111 (e.g., a housing) has a CTE greater than that of the insulating member 114 and the conductor 112, thereby forming a compression seal.

[0062] In the method of forming the feedthrough assembly 110, a glass preform may be positioned around a portion of the conductive element 112. The glass preform may comprise a filler glass composition as described herein. At least a portion of the glass preform may be positioned within an aperture 106 of the substrate 111 or within a sleeve member. The glass preform may be softened or completely melted to form a glass insulating member 114 that is sealingly engaged with the conductive element 112 and with an aperture 106 of the substrate 111 or the sleeve member. In some embodiments, it is not necessary to use one or more forming weights to soften or completely melt the glass preform to form the glass insulating member 114 that is sealingly engaged with the conductive element 112 and with an aperture 106 of the substrate 111 or the sleeve member. In some embodiments, softening or completely melting the glass preform does not cause the conductive element 112 to undergo a phase transition, nor does it cause the substrate 111 or the sleeve member to undergo a phase transition, thereby preventing these components from warping or deforming.

[0063] The first substrate 111 includes a first surface 116a (also referred to as a ceramic or glass housing material), a second surface 116b (e.g., silicon material), a length x1, a width x2, a thickness x3, and an aperture 106 for receiving the feedthrough assembly 110. The first substrate 111 includes the hermetically sealed feedthrough assembly 110 and metallized traces for establishing an electrical connection with the second substrate 128. In one embodiment, the first substrate 111 comprises ceramic or glass with a coefficient of thermal expansion (CTE) value equal to or greater than that of the feedthrough assembly 110 (e.g., a pin / glass assembly).

[0064] In one embodiment, the first substrate 111 may comprise a material having a CTE value equal to or greater than that of the conductive element 112 and the glass insulating member 114. The first substrate 111 may comprise ceramics, such as polycrystalline alumina with a CTE of 8.0, sapphire with a CTE of 8.0 (e.g., single-crystal alumina), and zirconium oxide with a CTE of 10. In another embodiment, the first substrate 111 or the housing may be made of glass instead of ceramic and has the general characteristics that (1) the glass has a higher melting point than the insulating member 114; and / or (2) the glass has a CTE value equal to or greater than that of the sealing glass.

[0065] The second substrate 128 includes vias 122, metallized traces 120, and electronic components that allow the MEMS package 110 to be used as a sensor substrate (e.g., a converter); however, those skilled in the art will understand that the substrate can be configured to include any type of circuitry (e.g., switches), signal processing capabilities, and / or any other suitable form of circuitry in relation to an implantable medical device. The second substrate 128 has approximately the same or similar dimensions to the first substrate 111. For example, the thickness X4 can be the same or approximately the same as X3. A wall thickness X5 forms a periphery on the first surface 130 of the second substrate 128. A second surface (not shown) of the second substrate 128 can be adjacent to the housing of the implantable medical device.

[0066] The feedthrough assembly 110 disposed in the first substrate 111 can then be coupled to the second substrate 128 (also referred to as a silicon MEMS substrate) via a junction 118 (e.g., a glass frit junction). The coupling of the first substrate 111 to the second substrate 128 can be achieved by using a glass frit, a gold-silicon eutectic material, or other suitable material 118. The second substrate 128 (silicon) material typically has a higher melting point than the filler glass used to form the glass insulating member 114. The conductive element 110 can be electrically connected to the second substrate 128 via a metal trace 120. In one embodiment, the metal trace 120 may be located, for example, within the second substrate 128.

[0067] Exemplary dimensions of the components in the MEMS package 100 include the following (however, those skilled in the art will understand that other dimensions may also be used): Diameter of conductive element 112 = 0.40 mm; Diameter of glass insulating member 114 = 0.75 mm; Length x1 = 3.50 mm; Width x2 = 1.00 mm; Thickness x3 = 0.40 mm; Thickness x4 = 0.25 mm; Wall x5 = 0.25 mm

[0068] Those skilled in the art will understand that other embodiments can implement the principles described herein. For example, functional unit 20 can be placed within a free body, such as a lead. Furthermore, although a MEMS package is described in relation to a sensor or sensor component (e.g., a converter), it is contemplated that the MEMS package 100 can be used in various ways to realize certain functions of an implantable medical device.

[0069] Figure 3 and 4 The images shown are isometric and cross-sectional views of a single-pole (single-pin) feedthrough assembly 200 having a tail pin 202 extending therethrough. However, it should be understood that the teachings of this disclosure are applicable to feedthrough assemblies that include multiple tail pins, as well as those that do not. Feedthrough assemblies that do not include tail pins, such as those described in U.S. Patent No. 5,902,326 to Lessar et al., are sometimes referred to as “optical” feedthroughs.

[0070] Assembly 200 includes a generally cylindrical sleeve 204 having a cavity through which pin 202 passes. Sleeve 204 is made of a conductive material (e.g., titanium alloy) and is configured to be securely coupled (e.g., welded) to a container of a device (e.g., a medical device) to be hermetically sealed. Insulating structure 206 is disposed within sleeve 204 to secure pin 202 relative to sleeve 204 and to electrically isolate pin 202 from sleeve 204. Insulating structure 206 includes a support structure 208 and a connector-insulator sub-assembly 210, both disposed around the tail pin 202. In various embodiments, insulating structure 206 may be without support structure 208. As will be described more fully below, connector-insulator sub-assembly 210 serves as an insulating seal and may take the form of, for example, a brazed joint or a glass seal (e.g., a filled glass seal, i.e., a glass seal containing the filled glass described herein). The support structure 208 may be made of a non-conductive material (e.g., polyimide) and abuts against the inner wall 212 disposed within the sleeve 204.

[0071] like Figure 4As can be seen, the connector-insulator subassembly 210 comprises three main components: an insulating ring 214 (e.g., made of ceramic material) that insulates the pin 202 from the sleeve 204; a pin-insulator seal 216 (e.g., made of brazed metal or glass) that connects the insulating ring 214 to the pin 202; and an insulator-sleeve seal 218 (e.g., made of brazed metal or glass) that connects the insulating ring 214 to the sleeve 204. The insulating ring 214 may include a bottom portion 215, a top portion 217, and an inner diameter portion 219. The inner diameter portion 219 defines an orifice through which the tail pin 202 extends.

[0072] In various embodiments of this disclosure, one or both of the pin-insulator seal 216 and the insulator-sleeve seal 218 may be formed from the filler glass composition described above.

[0073] The connector-insulator subassembly 210 is exposed along the bottom surface of the sleeve 204. When the sleeve 204 is securely attached to the container of the medical device, for example, the bottom portion 215 and therefore the lower portion of the connector-insulator subassembly 210 are exposed to bodily fluids. Therefore, it is important that the connector-insulator subassembly 210 forms an airtight seal between the sleeve 204 and the tail pin 202. A leak test can be performed on the connector-insulator subassembly 210. To allow this test to be performed, the orifice 220 ( Figure 3 The gas passes through sleeve 204 and is positioned within an internal annular cavity formed by the outer surface of the connector-insulator subassembly 210, the lower surface of the support structure 208, and the inner surface of sleeve 204. Gas is introduced into the internal annular cavity through orifice 220, which is plugged. Preferably, a low molecular weight gas (e.g., helium or hydrogen) is selected so that it can easily penetrate small openings in the connector-insulator subassembly 210. This allows gas to be introduced into the top portion 217 if other aspects are blocked (e.g., due to the filter capacitor being fully bonded to the pin and sleeve). The feedthrough 200 is then monitored, for example, by a mass spectrometer (e.g., at the bottom portion 215), to determine the presence of gas adjacent to the connector-insulator subassembly 210. If no gas is detected, it is concluded that the connector-insulator subassembly 210 has formed a satisfactory seal.

[0074] refer to Figures 5 to 7 This paper describes a method for manufacturing an exemplary feedthrough assembly. A sleeve 300 may include a recess 302 into which an insulating structure 310 can be inserted. The recess 302 may be bounded by a wall portion 304 and further includes a ledge 306 on which the inserted insulating structure 310 can be placed, such that the insulating structure 310 abuts against the ledge 306. The recess 302 may also define an opening 308 through which a tail pin 330 can extend.

[0075] The insulating structure 310 may include a top portion 312, a bottom portion 314, and an inner diameter portion 316, the inner diameter portion defining an aperture 318 extending from the top portion 312 to the bottom portion 314. In various embodiments, the insulating structure 310 may include an angled portion 317 that assists the tail pin 330 in engaging with the insulating structure 310, as described more fully below.

[0076] In various embodiments of this disclosure, the insulating structure 310 is inserted into the recessed portion 302, and the tail pin 330 is inserted into the orifice 318. A glass preform 320 can be fitted around the insulating structure 310, and a second glass preform 325 can be fitted around the tail pin 330. In various embodiments, a chamfer 305 may be included in the wall portion 304 to more securely position the glass preform 320 adjacent to the insulating structure 310. Furthermore, the insulating structure may include an angled portion 317 to more securely position the glass preform 325 adjacent to the tail pin 330.

[0077] After heat 350 is applied, the glass preform 320 softens or partially or completely melts and flows into the recess 302 between the insulating structure 310 and the wall portion 304. In this way, the glass preform 320 forms a glass seal 320A, which securely fixes the insulating structure 310 to the sleeve 300, as... Figure 7 As shown. Depending on the composition of the preform used, different types of energy (e.g., radiation, microwaves, magnetism) can be used to replace or supplement heat 350. A glass seal 325A can be formed between the tail pin 330 and the insulating structure 310 using the same or similar methods. The use of one of the glass seals 320A and 325A with brazing or other sealing compositions (e.g., glass seal 320A used with brazing to seal the tail pin 330 through the insulating structure 310; or glass seal 325A used with brazing to seal the sleeve 300 through the insulating structure 310) is within the scope of this disclosure.

[0078] In various embodiments of this disclosure, glass preforms 320, 325 and glass seals 320A, 325A may be formed from the filler glass compositions described above.

[0079] It should be understood that the various aspects disclosed herein can be combined in combinations different from those specifically given in the specification and drawings. It should also be understood that, depending on the example, certain actions or events of any process or method described herein may be performed in a different order, and may be added, combined, or omitted entirely (e.g., all described actions or events may not be necessary for performing the described technology). Furthermore, although some aspects of this disclosure are described for clarity as being performed by a single module or unit, it should be understood that the technology of this disclosure may be performed by a combination of units or modules associated with, for example, a medical device.

[0080] In one or more instances, the features of a medical device system as described herein may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functionality may be stored as one or more instructions or code on a computer-readable medium and executed by a hardware-based processing unit. The computer-readable medium may include non-transitory computer-readable media, which corresponds to tangible media 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).

[0081] Instructions can 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 arrays (FPGAs), or other equivalent integrated or discrete logic circuits. Therefore, the term "processor" as used herein can refer to any of the foregoing structures or any other physical structure suitable for implementing the described techniques. Furthermore, these techniques can be fully implemented in one or more circuit or logic elements.

[0082] The full disclosures of the patents, patent documents, and publications cited herein are incorporated by reference in their entirety as if each were individually incorporated. In the event of any conflict or difference between this written specification and the disclosures in any document incorporated herein by reference, the written specification shall prevail. Various modifications and alterations to this disclosure will become apparent to those skilled in the art without departing from the scope and spirit of this disclosure. It should be understood that this disclosure is not intended to be unduly limited by the illustrative embodiments and examples set forth herein, and such examples and examples are presented by way of example only, while the scope of this disclosure is intended to be limited only by the following claims set forth herein.

Claims

1. A feedthrough assembly comprising: a sleeve; an insulating structure; and a first glass seal securely fixing the insulating structure within the sleeve, the first glass seal comprising a first glass and first single phase particles dispersed therein; wherein the first glass comprises: 25% to 40% B203; 0 to 25% CaO; 0 to 25% MgO; 0 to 25% SrO; 0 to 10% La203; 5% to 15% Si02; and 10% to 20% Al203; wherein all percentages are mole percent of the glass.

2. The feedthrough assembly of claim 1, wherein the first glass comprises 30% to 50% of a component selected from the group consisting of CaO, MgO, SrO, and combinations thereof, provided that the content of each of CaO, MgO, and SrO does not exceed 25%.

3. The feedthrough assembly of claim 2, wherein the first glass comprises 30% B203, 5% La203, 10% Si02, 15% Al203, and 30% to 50% of a component selected from the group consisting of CaO, MgO, and combinations thereof, provided that the content of each of CaO and MgO does not exceed 25%.

4. The feedthrough assembly of any one of claims 1 to 3, wherein the first glass further comprises up to 10% Mn02.

5. The feedthrough assembly of any one of claims 1 to 3, wherein the first glass comprises 30% B203, 20% CaO, 20% MgO, 5% La203, 10% Si02, and 15% Al203.

6. The feedthrough assembly of any one of claims 1 to 3, further comprising at least one tail pin, wherein the insulating structure comprises a top portion, a bottom portion, and an inner diameter portion, wherein the inner diameter portion defines at least one aperture extending from the top portion to the bottom portion, and wherein the at least one tail pin extends through the at least one aperture.

7. The feedthrough assembly of claim 6, further comprising a gold braze sealing the at least one tail pin with the insulating structure.

8. The feedthrough assembly of claim 6, further comprising a second glass seal sealing the at least one tail pin with the insulating structure.

9. The feedthrough assembly of claim 8, wherein the second glass seal comprises a second glass and second single phase particles dispersed therein; wherein the second glass comprises: 25% to 40% B203; 0 to 25% CaO; 0 to 25% MgO; 0 to 25% SrO; 0 to 10% La203; 5% to 10% Si02; and 10% to 20% Al203; wherein all percentages are mole percent of the glass. ​ 10. The feedthrough assembly of claim 9, wherein the second glass comprises 30% to 50% of a component selected from the group consisting of CaO, MgO, SrO, and combinations thereof, provided that the content of each of CaO, MgO, and SrO does not exceed 25%.

11. The feedthrough assembly of claim 10, wherein the second glass comprises 30% B203, 5% La203, 10% Si02, 15% AI2O3, and 30% to 50% of a component selected from the group consisting of CaO, MgO, and combinations thereof, provided that the content of each of CaO and MgO does not exceed 25%.

12. The feedthrough assembly of any one of claims 9 to 11, wherein the second glass further comprises up to 10% Mn02.

13. The feedthrough assembly of any one of claims 9 to 11, wherein the second glass comprises 30% B203, 20% CaO, 20% MgO, 5% La203, 10% Si02, and 15% AI2O3.

14. The feedthrough assembly of any one of claims 1 to 3, wherein the sleeve includes a wall portion and a ledge, the insulating structure abuts the ledge, and the first glass seal securely affixes the insulating structure to the wall portion.

15. The feedthrough assembly of any one of claims 9 to 11, wherein the first and / or second single-phase particles comprise AI2O3, Y2O3, Zr02, Ti02, MgO, ZnO, BaO, CaO, Nb205, Ta205, SiC, Si3N4, or mixtures thereof.

16. The feedthrough assembly of any one of claims 9 to 11, wherein the first glass seal comprises at least 1 wt-% of the first single-phase particles and / or the second glass seal comprises at least 1 wt-% of the second single-phase particles, based on the total weight of the glass and particles.

17. The feedthrough assembly of any one of claims 9 to 11, wherein the first glass seal comprises up to 25 wt-% of the first single-phase particles and / or the second glass seal comprises up to 25 wt-% of the second single-phase particles, based on the total weight of the glass and particles.

18. A feedthrough assembly comprising: a sleeve; an insulating structure comprising a top portion, a bottom portion, and an inner diameter portion, wherein the inner diameter portion defines at least one aperture extending from the top portion to the bottom portion; at least one tail pin extending through the at least one aperture; and a glass seal securely affixing the at least one tail pin with the insulating structure, the glass seal comprising a glass and single-phase particles dispersed therein; wherein the glass comprises: 25% to 40% B203; 0 to 25% CaO; 0 to 25% MgO; 0 to 25% SrO; 0 to 10% La203; 5% to 15% Si02; and 10% to 20% AI2O3; wherein all percentages are in mole percent of the glass. ​ 19. The feedthrough assembly of claim 18, wherein the glass comprises 30% to 50% of a component selected from the group consisting of CaO, MgO, SrO, and combinations thereof, provided that the content of each of CaO, MgO, and SrO does not exceed 25%.

20. The feedthrough assembly of claim 18 or 19, wherein the single-phase particles comprise AI2O3, Y2O3, ZrO2, TiO2, MgO, ZnO, BaO, CaO, Nb2O5, Ta2O5, SiC, Si3N4, or mixtures thereof.

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