Feedthrough assembly using laser technology to create a glass-to-metal seal

Abstract

The present invention relates to an electrical feedthrough (1), comprising: a metallic flange (2) comprising a first side (2a), a flat electrically insulating member (3) being transparent to laser light (L), the electrically insulating member (3) comprising an outer circumferential edge region (30) being arranged on the first side (2a) of the flange (2), wherein the edge region (30) is hermetically joined to the first side (2a) by a weld seam (4), and wherein the electrically insulating member (3) comprises at least a first through-hole (31) delimited by a first circumferential inner edge region (310), and at least a first electrical contact member (5), the first electrical contact member (5) comprising a first side (5a) being arranged at the first inner edge region (310) of the at least one first through-hole (31) and hermetically joined to the first inner edge region (310) of the at least one first through-hole by a first weld seam (6).

Description

[0001] Applicant: BIOTRONIK SE & Co. KG

[0002] Date: 03.11.2025

[0003] Our Reference: 23.137P-WO

[0004] Feedthrough assembly using laser technology to create a glass-to-metal seal

[0005] The present invention relates to an electrical feedthrough, particularly for an implantable medical device, and to a method for producing an electrical feedthrough as well as to devices, particularly implantable medical devices, comprising an electrical feedthrough according to the present invention.

[0006] Hermetic feedthroughs usually require vacuum technology and high temperatures above 1000°C. Particularly, standard ceramic feedthroughs are brazed to metallic components (e.g., a housing) using gold as a solder, while standard glass feedthroughs are based on a melted glass seal.

[0007] Typically, known hermetic feedthroughs mentioned above need a sophisticated high temperature vacuum process to be manufactured. This is an expensive batch process.

[0008] Based on the above, the problem to be solved by the present invention is to provide an electrical feedthrough that can be produced in an efficient manner allowing automation as well as small footprints of the electrical feedthrough.

[0009] This problem is solved by an electrical feedthrough having the features of claim 1. Preferred embodiments of this aspect of the present invention are stated in the corresponding dependent claims and are described below. Further aspects of the present invention relate to devices, particularly implantable medical devices, comprising an electrical feedthrough according to the present invention as well as to methods for producing an electrical feedthrough according to the present invention. According to claim 1, an electrical feedthrough, particularly for an implantable medical device is disclosed, comprising: a metallic flange comprising a first side and a second side facing away from the first side, a flat electrically insulating member being transparent to laser light, the electrically insulating member comprising an outer circumferential edge region being arranged on the first side of the flange, wherein the outer edge region is hermetically joined to the first side by a first weld seam (e.g. forming a glass-to-metal bond), and wherein the electrically insulating member comprises at least a first through-hole delimited by a first inner circumferential edge region, and at least a first electrical contact member, the first electrical contact member comprising a first side being arranged at the first inner edge region of the at least one first through- hole and hermetically joined to the first inner edge region of the at least one first through-hole by a second weld seam (e.g. forming a glass-to-metal bond).

[0010] The present invention allows to create a very small electrical feedthrough suitable for miniature implants (such as pressure sensors, bio-monitors, implantable leadless pacemakers and the like) at a very low price in high quantities. Implants do often have a hermetic housing that protects the implants electronic hardware from the body environment, especially from bodily fluids that would harm the electronic circuits accommodated in the housing. At the same time electrical signals have to be conveyed through the hermetic housing in order to perform the intended function of the implant. Particularly, the electrical feedthrough according to the present invention provides these functions. Furthermore, batteries usually have a hermetic housing that ensures that no battery electrolytes or alike escape the battery housing. This is especially important for implants since electrolytes may have harmful properties for human beings. Particularly, the electrical feedthrough according to the present invention may also be used in such applications.

[0011] Particularly, the present invention makes use of laser welding technology in an advantageous fashion to produce a hermetic seal that enables a wafer-like production of electrical feedthroughs, which may be used, for example monitoring device having a dipole design, sensors, and communication devices. Particularly, the electrical feedthrough according to

[0012] 23.137P-WO | 03.11.2025 the present invention may be welded to a metal housing or a glass housing and may further carry additional components such as sensor and communication components.

[0013] Furthermore, particularly, the invention uses a transparent material such as a glass as part of the electrical feedthrough and particularly as part of an implant housing material. Advantageously, this enables transmission of electro-magnetic communication, i.e., RF communication, through the housing and allows to accommodate corresponding communication devices in an interior space of the housing. Otherwise, in metallic feedthroughs, the communication antenna has to be placed outside the housing (e.g. in a header). In a preferred embodiment, the electrically insulating member is made out of or comprises a glass (see also examples below). Alternatively, the transparent electrically insulating member may also be formed out of or comprise a plastic material, particularly a polymer (see also examples below).

[0014] Particularly, the at least a portion of the first side of the metallic flange, which is joined with the electrically insulating member, is flat or planar. In one embodiment, the entire fist side of the metallic flange is planar or flat.

[0015] Further, according to an embodiment of the present invention, the first weld seam and / or the second weld seam is a laser-welded weld seam.

[0016] Furthermore, according to an embodiment of the invention, the electrically insulating member comprises a second through hole delimited by a second inner edge region, and the electrical feedthrough comprises a second electrical contact member, the second electrical contact member comprising a first side being arranged at the second inner edge region of a second through-hole and hermetically joined to the second inner edge region of the second through-hole by a third weld seam (e.g. forming a glass-to-metal bond). In one embodiment, the third weld seam is a laser-welded seam. Further, in an embodiment, the second electrical contact member is integrally formed with the flange. Particularly, the flange and the first and / or second electrical contact member are metallic or comprise at least a metallic surface portion to form e.g. a glass-to-metal bond with the electrically insulating member, which bond is particularly generated by means of laser welding.

[0017] 23.137P-WO | 03.11.2025 According to one embodiment of the invention, the flange comprises an outside facing away from an interior of a housing when the electrical feedthrough is connected to the housing via the flange, wherein said outside is formed by the first side of the flange or faces away from the first side.

[0018] Furthermore, in an embodiment of the invention the electrical contact members and the flange are arranged on the same side of the electrically insulating member. In an alternative embodiment, the electrical contact members and the flange are arranged on different sides of the electrically insulating member.

[0019] According to an embodiment of the invention, the electrical feedthrough comprises a ring member, wherein the electrically insulating member is arranged between the ring member and the flange, and wherein particularly the ring member extends further outwards in the radial direction of the ring member than the weld seam that connects the electrically insulating member to the flange.

[0020] According to an embodiment of the invention, the first electrical contact member comprises a through-hole for filling in a liquid. This through-hole may be used for filling an electrolyte into an interior space of a housing of a battery when the electrical feedthrough is used as a lid of the battery (or as a portion of a lid of the battery). Here, the flange of the electrical feedthrough may be welded to the housing of the battery.

[0021] Particularly, according to a further embodiment, the first electrical contact member may comprise a step defining a protrusion of the first electrical contact member that is arranged in the first through-hole of the electrically insulating member in a form-fitting manner.

[0022] Furthermore, according to an embodiment of the invention, the first electrical contact member is a first flat electrical contact member or comprises a first flat base and a first feedthrough pin protruding from the first flat base, particularly from an outside of the electrical feedthrough or in opposite directions, i.e., from said outside and from an inside of the electrical feedthrough. Alternatively, or in addition, in an embodiment, the second

[0023] 23.137P-WO | 03.11.2025 electrical contact member is a second flat electrical contact member or comprises a second flat base and a second feedthrough pin protruding from the second flat base, particularly from an outside of the electrical feedthrough or in opposite directions, i.e., from said outside and from an inside of the electrical feedthrough.

[0024] Further, according to yet another embodiment of the invention, the electrical feedthrough comprises an electrically conductive track which may be a functional component of a pressure sensor, wherein this conductive track is arranged on the electrically insulating member. Particularly, in an embodiment, the conductive track preferably comprises a meandering shape. Furthermore, in an embodiment, the electrically conductive track is arranged on an outside of the electrically insulating member (e.g. it is arranged on an outside of a device when the electrical feedthrough is connected to a housing of said device) or on an inside of the electrically insulating member (e.g. the conductive track is arranged on an inside of a device when the electrical feedthrough is connected to a housing of said device).

[0025] Furthermore, according to an embodiment of the invention, a planar communication coil is arranged on the electrically insulating member. Particularly, the electrically conductive track is arranged on an outside of the electrically insulating member or on an inside of the electrically insulating member.

[0026] According to a further aspect of the present invention, a device is disclosed, wherein the device comprises a housing and an electrical feedthrough according to the present invention, wherein the flange of the electrical feedthrough is connected (particularly welded, particularly laser-welded) to the housing. In an embodiment of the device, the device is an implantable medical device, wherein particularly the housing accommodates an operational electronic circuitry, wherein particularly the electronic circuitry is configured to perform a therapeutic function, e.g., application of therapeutic electrical signals to cardiac or nerve tissue and / or sense physiological signal, e.g., electrical physiological signal form cardiac or nerve tissue. In a further embodiment of the device, the device is a battery, and the electrical feedthrough forms a lid of the battery or a portion of a lid of the battery.

[0027] 23.137P-WO | 03.11.2025 According to a further aspect of the present invention, a device is disclosed, particularly an implantable medical device, the device comprising a first electrical feedthrough according to the invention and a second electrical feedthrough according to the invention, wherein the device further comprises a first battery and an intermediary housing arranged between and connected to the first and the second electrical feedthrough, and wherein the device further comprises an electronic module accommodated in an interior space of the intermediary housing, and wherein the first electrical feedthrough is connected to a housing of the first battery.

[0028] In one embodiment of the device, the intermediary housing and the housing of the battery are made from an electrically conductive material, respectively, and the intermediary housing is electrically insulated from the housing of the first battery by the first electrical feedthrough, wherein particularly the first electrical feedthrough comprises a ring member as described above, wherein the ring member is joined, particularly welded, with the housing of the first battery, wherein particularly the device is designed as a cardiac monitor, wherein the intermediate housing forms a first electrode pole of the device, and the housing of the first battery forms a second electrode pole.

[0029] In one embodiment of the device, the intermediary housing and the housing of the battery are made from an electrically conductive material, respectively, and the intermediary housing is joined, particularly welded, with the housing of the first battery in an electrically conductive fashion, i.e., the intermediary housing is not electrically insulated from the housing of the first battery, wherein the device comprises a first electrode electrically connected to a first electrical contact member (as described above), and the intermediary housing and / or the housing of the first battery forms a second electrode, wherein particularly the device is designed as stimulation device, e.g., a cardiac pacemaker, particularly an intracardiac pacemaker.

[0030] According to an embodiment of the device, the device comprises a second battery, wherein the second electrical feedthrough is connected to a housing of the second battery. In one embodiment of the device, the housing of the first battery and the housing of the second battery are made from an electrically conductive housing, wherein the housing of the first

[0031] 23.137P-WO | 03.11.2025 battery is electrically insulated from the housing of the second battery, particularly by the first electrical feedthrough and / or by the second electrical feedthrough, wherein particularly, the device is designed as a cardiac monitoring device, wherein the housing of the first battery forms a first electrode pole, and the housing of the second battery forms a second electrode pole.

[0032] According to yet another aspect of the present invention, an device is disclosed, particularly in the form of an implantable medical device, the device comprising: a flat metallic flange comprising a first side (and particularly a second side facing away from the first side), and a flat electrically insulating member being transparent to laser light, the electrically insulating member comprising a circumferential outer edge region being arranged on the first side of the flange, wherein the outer edge region is hermetically joined to the first side by a weld seam (particularly forming a glass-to-metal bond), and wherein an electrically conductive track is arranged on the electrically insulating member.

[0033] According to an embodiment of the device, the electrically conductive track is arranged on an outside of the electrically insulating member or on an inside of the electrically insulating member. According to a further embodiment of the device, the device comprises a housing defining an interior space of the housing, wherein the electrical feedthrough is connected to the housing. Particularly, said outside faces away from the interior space, whereas said inside faces the interior space of the housing.

[0034] Furthermore, in an embodiment of the device, the conductive track comprises a meandering shape, wherein particularly the conductive track forms part of a pressure sensor.

[0035] According to yet another embodiment of the device, further preferred embodiment, the conductive track forms a planar communication coil for sending and / or receiving radio signals.

[0036] 23.137P-WO | 03.11.2025 According to a further aspect of the present invention, a method for producing an electrical feedthrough is disclosed, particularly an electrical feedthrough according to the present invention, particularly for an implantable medical device. The method comprises:

[0037] - providing a flat metallic flange comprising a first side (and particularly a second side facing away from the first side),

[0038] - providing a flat electrically insulating member being transparent to laser light, the electrically insulating member comprising a circumferential outer edge region and at least a first through-hole delimited by a first circumferential inner edge region,

[0039] - providing at least a first electrical contact member, the at least one first electrical contact member comprising a first side,

[0040] - arranging the electrically insulating member with its outer edge region on the first side of the flange, and

[0041] - generating a first weld seam (e.g. forming a glass-to-metal bond) by laser-welding the outer edge region to the first side of the flange, wherein laser light applied to the electrically insulating member and flange upon laser welding travels through the electrically insulating member before impinging on the first side of the flange,

[0042] - arranging the electrically insulating member with its first inner edge region of the at least one through-hole on the first side of the at least one first electrical contact member, and

[0043] - generating a second weld seam (e.g. forming a glass-to-metal bond) by laser-welding the first inner edge region of the at least one first through-hole of the electrically insulating member to the first side of the at least one first electrical contact member, wherein laser light applied to the electrically insulating member and the at least one first electrical contact member upon laser welding travels through the electrically insulating member before impinging on the first side of the at least one first electrical contact member.

[0044] According to an embodiment, the laser light is generated by at least one laser, wherein the laser is pulsed laser, particularly an ultra-short-pulse Laser, a fs (femtosecond)-laser, a ps (picosecond)-laser., In one embodiment, the laser is characterized by a power in the range of 0.5 W to 5 W. In one embodiment, the laser is a NIR-laser, particularly emitting laser light having a wavelength of about 1030 nm. In one embodiment, the laser generates laser

[0045] 23.137P-WO | 03.11.2025 light with a pulse frequency in the range of 500 kHz to 10 Mhz. In one embodiment, laser light is applied with a translation speed in the ranged of 10 mm / s to 100 mm / s. In one embodiment, the first weld seam and / or the second weld seam is generated with laser welding spots having a diameter in the range of 25 pm to 75 pm. In one embodiment, the first weld seam and / or the second weld seam comprise multiple (parallel) weld lines having a distance to one another of approx. 50 pm.

[0046] Particularly, welding the electrically insulating member to the flange and to the at least one electrical contact member may be conducted in any desired order, particularly also at the same time. Particularly, all components may be at first arranged with respect to the electrically insulating member and welded thereafter. It is however also conceivable to arrange and laser-weld the components one after the other.

[0047] According to an embodiment of the method, the method further comprises providing a second electrical contact member, the second electrical contact member comprising a first side, wherein the electrically insulating member further comprises a second through-hole delimited by a second circumferential inner edge region, and arranging the electrically insulating member with its second inner edge region of the second through-hole on the first side of the second electrical contact member, and generating a third weld seam (e.g. forming a glass-to-metal bond) by laser-welding the second inner edge region of the second through- hole of the electrically insulating member to the first side of the second electrical contact member, wherein laser light applied to the electrically insulating member and the second electrical contact member upon laser welding travels through the electrically insulating member before impinging on the first side of the second electrical contact member.

[0048] Furthermore, according to an embodiment of the method, the second electrical contact member is integrally connected to the flange.

[0049] Materials for the flange and the first and / or second electrical contact member may be selected as described above in conjunction with the electrical feedthrough according to the present invention (see also examples stated below).

[0050] 23.137P-WO | 03.11.2025 Further, according to yet another embodiment of the method, the flange is connected to a housing of a medical device, particularly of an implantable medical device, wherein the flange comprises an outside facing away from an interior of the housing, wherein said outside is formed by the first side of the flange or faces away from the first side.

[0051] In a further embodiment of the method, the (first and second) electrical contact members and the flange are arranged on the same side of the electrically insulating member, or wherein the electrical contact members and the flange are arranged on different sides of the electrically insulating member.

[0052] According to a further embodiment of the method, the electrical feedthrough comprises a ring member, wherein the electrically insulating member is arranged between the ring member and the flange, and wherein particularly the ring member extends further outwards in the radial direction of the ring member than the weld seam that connects the electrically insulating member to the flange.

[0053] According to yet another embodiment of the method, the method further comprises the step of connecting the electrical feedthrough to a housing of a battery to form the battery, wherein the first electrical contact member comprises a through-hole, and wherein the method comprises the further step of filling an electrolyte through the through hole into an interior space of said housing of the battery. Particularly, the electrical feedthrough may be connected to the housing by welding the flange to the housing. Furthermore, particularly, according to an embodiment, the first electrical contact member comprises a step defining a protrusion of the electrical contact member that is arranged in the first through-hole of the electrically insulating member in a form-fitting manner.

[0054] According to a further embodiment of the method, the first electrical contact member is a first flat electrical contact member or comprises a flat first base and a first feedthrough pin protruding from the first base, particularly from an outside of the electrical feedthrough or in opposite directions, i.e., from said outside and from an inside of the electrical feedthrough, and / or wherein the second electrical contact member is a second flat electrical contact member or comprises a second flat base and a second feedthrough pin protruding from the

[0055] 23.137P-WO | 03.11.2025 base, particularly from an outside of the electrical feedthrough or in opposite directions, i.e., from said outside and from an inside of the electrical feedthrough.

[0056] Furthermore, according to a further embodiment of the method, an electrically conductive track for a pressure sensor is arranged on the electrically insulating member, wherein particularly the conductive track comprises a meandering shape. Furthermore, the electrically conductive track is arranged on an outside of the electrically insulating member or on an inside of the electrically insulating member. Particularly, said outside an inside are defined with respect to a housing to which the flange can be connected, wherein the outside refers to a side facing away from an interior space defined by the housing, wherein the inside refers to a side facing towards said interior space.

[0057] In the following, embodiments of the present invention as well as further features and advantages of the present invention shall be described with reference to the Figures, wherein

[0058] Fig. 1 shows a perspective view of an embodiment of an electrical feedthrough according to the present invention,

[0059] Fig. 2 shows a cross-sectional view of the embodiment of Fig. 1,

[0060] Fig. 3 shows a further embodiment of an electrical feedthrough of the present invention,

[0061] Fig. 4 shows a perspective view of a further embodiment of an electrical feedthrough according to the present invention, wherein a second electrical contact member is integrally connected to a flange of the feedthrough,

[0062] Fig. 5 shows a cross-sectional view of the embodiment of Fig. 4,

[0063] Fig. 6 shows an embodiment of an electrical feedthrough being connected to a housing of an implantable medical device or of a battery,

[0064] 23.137P-WO | 03.11.2025 Fig. 7 shows an alternative embodiment of an electrical feedthrough being connected to a housing of an implantable medical device or of a battery, wherein an electrically insulating member of the feedthrough is arranged on an inside of a flange of the feedthrough (in contrast to Fig. 6),

[0065] Fig. 8 shows a further embodiment of an electrical feedthrough being connected to a housing of an implantable medical device, wherein the electrically insulating member of the feedthrough is arranged on the inside of the flange, too,

[0066] Fig. 9 shows a perspective view of a further embodiment of an electrical feedthrough according to the present invention, wherein a ring member is welded to the electrically insulating member in addition so that the electrically insulating member is arranged between the ring member and the flange,

[0067] Fig. 10 shows a cross-sectional view of the embodiment of Fig. 9,

[0068] Fig. 11 shows an embodiment of a method according to the present invention,

[0069] Fig. 12 shows a perspective view of a further embodiment of an electrical feedthrough according to the present invention, wherein in contrast to the embodiment shown in Fig. 9, the contact members are arranged on an outside of the electrically insulating member,

[0070] Fig. 13 shows a cross-sectional view of the embodiment of Fig. 12,

[0071] Fig. 14 shows an embodiment of an assembly according to the present invention using two electrical feedthroughs according to the present invention,

[0072] Fig. 15 shows a further embodiment of an assembly according to the present invention using an electrical feedthrough according to the present invention,

[0073] 23.137P-WO | 03.11.2025 Fig. 16 shows a perspective view of a further embodiment of an electrical feedthrough according to the present invention, wherein the first contact member comprises a through-hole forming a filling hole,

[0074] Fig. 17 shows a cross-sectional view of the embodiment of Fig. 16,

[0075] Fig. 18 shows a cross-sectional view of a further embodiment of an electrical feedthrough of the present invention, wherein the contact members of the feedthrough comprise protrusions being arranged in openings of the electrically insulating member of the feedthrough in a form-fitting manner,

[0076] Fig. 19 shows a cross-sectional view of a further embodiment of an electrical feedthrough of the present invention, wherein the contact members of the feedthrough comprise feedthrough pins protruding outwards,

[0077] Fig. 20 shows a cross-sectional view of a further embodiment of an electrical feedthrough of the present invention, wherein the feedthrough pins protrude inwards and outwards,

[0078] Fig. 21 shows a perspective view of an embodiment of an assembly according to the present invention, wherein the assembly comprises an electrically insulating member welded to a flange and an electrically conductive track for a pressure sensor, the track being arranged on the electrically insulating member,

[0079] Fig. 22 shows a cross-sectional view of the embodiment of Fig. 21,

[0080] Fig. 23 shows a perspective view of an embodiment of an assembly according to the present invention, wherein the assembly comprises an electrically insulating member welded to a flange and a planar communication coil arranged on the electrically insulating member,

[0081] Fig. 24 shows a cross-sectional view of the embodiment of Fig. 23,

[0082] 23.137P-WO | 03.11.2025 Fig. 25 shows a perspective view of an embodiment of an electrical feedthrough according to the present invention, wherein the feedthrough further comprises an electrically conductive track of a pressure sensor arranged on the electrically insulating member, particularly on an inside of the electrically insulating member,

[0083] Fig. 26 shows a variant of the embodiment of Fig. 25 with the flange, the conductive track and the contact members of the feedthrough being arranged on an outside of the electrically insulating member, and

[0084] Fig. 27 shows a variant of the embodiment of Figs. 25 and 26 with the flange and the conductive track arranged on an inside of the electrically insulating member and the contact members of the feedthrough being arranged on the outside of the electrically insulating member.

[0085] Fig. 1 shows in conjunction with Fig. 2 an embodiment of an electrical feedthrough 1 according to the present invention, wherein the electrical feedthrough 1 comprises a flat metallic flange 2 that may comprise an annular shape and further comprises a first side 2a and a second side facing away from the first side 2a. The feedthrough 1 further comprises a flat electrically insulating member 3 that may comprise a circular outer contour and is transparent to laser light L provided by at least one laser 14. Furthermore, the electrically insulating member 3 comprises an outer circumferential edge region 30 being arranged on the first side 2a of the flange 2, wherein the outer edge region 30 is hermetically joined to the first side 2a by a first weld seam 4 forming an e.g. glass-to-metal bond that may be generated by means of the laser light L provided by laser 14. Furthermore, the electrically insulating member 3 comprises at least a first through-hole 31 delimited by a first inner circumferential edge region 310 of the electrically insulating member 3, and at least a first electrical contact member 5, the first electrical contact member 5 comprising a first side 5a being arranged on the first inner edge region 310 of the at least one first through-hole 31 and hermetically joined to the edge region 310 of the at least one first through-hole 31 by a second weld seam 6 forming an e.g. glass-to-metal bond that may be generated by means of

[0086] 23.137P-WO | 03.11.2025 the laser light L provided by laser 14. As further shown in Fig. 1 the electrical feedthrough 1 may comprise a second electrical contact member 7, the second electrical contact member 7 comprising a first side 7a being arranged on a second inner circumferential edge region 320 of a second through-hole 32 of the electrically insulating member 3 and hermetically joined to the second inner edge region 320 of the second through-hole 32 by a third weld seam 8 forming an e.g. glass-to-metal bond that can be generated by means of the laser light L provided by laser 14. Suitable lasers 14 and laser light L are described herein. Particularly, the laser 14 is a pulsed laser, particularly an ultra-short pulse laser, e.g., a fs-laser or ps-laser, particularly with a power in the range of 0.5 W to 5 W, and a wavelength of 1030 nm. Particularly, laser light is applied with a pulse frequency in th range of 500 kHz to 10 Mhz. Furthermore, the first weld seam 4 and or the second weld seam 6 is generated with laser welding spots having a diameter in the range of 25 pm to 75 pm and may comprise multiple (parallel) weld lines having a distance to one another of approx. 50 pm.

[0087] Thus, the present invention utilizes the fact that the electrically insulating member 3 is transparent to the used laser light L so that the laser light L can impinge onto the underlying flange 2 and contact member(s) 5, 7 for generating the respective weld seam / bond.

[0088] Advantageously, the embodiment illustrated in Fig. 1 may be achieved with a comparatively small number of components. Particularly, only two layers of materials (i.e. the electrically insulating member 3 and the flange / contact members 2, 5, 7 and the afore-mentioned laser process are needed. The electrically insulating member forms the sole insulation material layer whereas the flange 2 and contact members 5, 7 form the electrically conductive layer. Both materials are joint and hermetically sealed to each other by the use of laser welding as described above. The laser light L travels through the laser light transparent material formed by the electrically insulating member 3 and heats up and melts the conductive base material below (i.e. flange 2 and electrical contact members 5, 7) to a temperature such that the insulating material layer (electrically insulating member 3) reaches its melting temperature / glass transition point temperature and creates a joint between the two materials, e.g., glass and metal. Fig. 1 indicates single weld seams 4, 6, and 8. However, multiple weld seams may be used per connection. Furthermore, a single laser 14 may be used to generate

[0089] 23.137P-WO | 03.11.2025 all the weld seams 4, 7, 8. Alternatively, multiple lasers 14 may be employed to generate the respective weld seams 4, 6, 8 between the respective components.

[0090] The shape of the flange 2 or of the complete feedthrough 1 may be chosen as desired. Fig. 1 shows is a circular design but also a rectangular, oval, or free-from shapes are possible. Also, the number of electrical contact members 5, 7 may be chosen as desired. Shown are only two electrical contact members 5, 7, but also only one or several, dozens or even hundreds of contact members are easily achievable with the technology described herein.

[0091] Generally, according to an embodiment of the present invention, the flange 2 may be formed out of or can comprise one of the following materials: an electrically conductive material (particularly a metal), a biocompatible material, a biocompatible electrically conductive material (particularly metal), titanium, a titanium alloy, a stainless steel, niobium, a niobium alloy, platinum, a platinum alloy, iridium, an iridium alloy, tantalum, a tantalum alloy. Furthermore, like the flange 2, the respective electrical contact member 5, 7 may also be selected from the above-stated list of materials. Furthermore, the electrical contact member(s) 5, 7 may be coated before assembly to achieve low contact resistance (e.g., with ENIG [Electroless Nickel Immersion Gold], gold etc.), particularly for spring contacts.

[0092] The components of the conductive layer, i.e., the flange 2 and / or electrical contact member(s) 5, 7 may be also created by additive manufacturing, especially using SLM (selective laser melting) or EBM (Electron beam welding) or FDM (fused deposition melting)

[0093] Furthermore, in a preferred embodiment, the electrically insulating member 3 is formed out of or comprises one of the following materials: an electrically insulating and transparent material, a glass, a glass alloy, soda-lime glass, borosilicate glass, neutral glass, aluminium silicate glass, quartz glass, sealing glasses, non-silicate glasses. However, for the electrically insulating member 3, also polymer materials such as POM, LCP, PMMA may be used for short term implants, since the moisture diffusion is a problem for long term implants. Or polymer materials with additional coatings as a diffusion barrier may be used. The electrically insulating layer 3 may also be created by additive manufacturing, especially

[0094] 23.137P-WO | 03.11.2025 using SLM (selective laser melting) or FDM (fused deposition melting). The above-stated materials of the flange 2, electrical contact member(s) 5, 7, and of the electrically insulating member 3 may be used in every embodiment described herein.

[0095] Furthermore, Fig. 3 illustrates a method of etching away a surplus material portion 33 (e.g. by chemical or laser etching). Particularly, said surplus material portion 33 may be a portion of a metallic layer from which the flange 2 and the electrical contact member(s) 5, 7 are to be formed by way of etching away the surplus material portion 33, as indicated in Fig. 3. However, this method of etching away a surplus material portion may also be applied to the electrically insulating member 3, i.e., to form the through-holes 31, 32 and / or an outer contour of the electrically insulating member 3. Etching may be performed by way of laser etching with ultra-short laser pulses having particularly wave lengths of e.g. 1030 nm, particularly with ultra-short pulses, e.g., 20 ps to 900 fs.

[0096] Further, Figs. 4 and 5 illustrate an embodiment of an electrical feedthrough 1 according to the present invention, wherein a GND connection may be provided to a housing material of an implant or a battery. Particularly, to achieve this, the second electrical contact member 7 of the embodiment shown in Figs. 1 and 2 may be integrally connected to the flange 2. This merged component 7 may then provide a contact that can be connected to the electronic module to transmit signals or energy from / to the housing (GND = ground) potential. The connection method can be realized by welding, soldering, conductive glueing, spring contacting, pogo-pin contacting, bonding or alike.

[0097] Figs. 6 to 8 show possible hermetic / fluid tight connections of the electrical feedthrough 1 shown in Figs. 4 and 5 (also the embodiments shown in Figs. 1 to 3 may be used) to an implant housing 10 or battery housing 10 by means of e.g. laser welding. Here, the flange 2 is welded to the adjacent housing 10 to achieve a connection between the electrical feedthrough 1 and the housing 10. Particularly, the flange 2 may act as a lid for closing the housing 10. Particularly, in Fig. 6, the flange 2 is welded to the housing 10 such that the first side 2a of the flange 2 faces away from an interior space of the housing 10 and may form a portion of an outside of the implant or battery. Alternatively, as shown in Fig. 7 or 8, the flange 2 may be welded to the housing 10 such that the first side 2a faces towards the interior

[0098] 23.137P-WO | 03.11.2025 space of the housing 10 and the contact member(s) 5, 7 are arranged on an outside of the housing 10. Particularly, the housing may be cylindrical, and the flange 2 may comprise a circular contour so that the flange 2 (acting as a lid) 1 may form a face side of the implant / battery. As shown in Fig. 8, the flange 2 of the electrical feedthrough 1 may also be welded to an edge of a through-hole formed in a planar surface portion of a housing 10.

[0099] Figs. 9 and 10 show yet another embodiment of an electrical feedthrough 1 according to the present invention, wherein here the electrically insulating properties of member 3 are used to separate implant potentials to e.g. create a large sensing vector. Particularly, a respective implantable medical device may be characterized by a dipole design, i.e., the medical device has two conductive housing portions (e.g., accommodating a battery and an electronic circuitry, respectively, or two batteries, see below), wherein each of the housing portions act as an electrode or electrode pole, respectively. For producing such a electrical feedthrough 1 suitable for an implantable medical device with a dipole device , the method illustrated in Fig. 11 may be used. Particularly, the electrical feedthrough 1 now comprises also a metallic ring member 9, wherein the electrically insulating member 3 is arranged between the ring member 9 and the flange 2, and wherein particularly the ring member 9 extends further outwards in the radial direction of the ring member 9 than the weld seam 4 that connects the electrically insulating member 3 to the flange 2 (cf. Fig. 1 ID). Particularly, for providing the electrical feedthrough 1, the electrically insulating member 3 may be arranged on the ring member 9 (cf. Fig. 11 A) and may be laser welded to the ring member 9 (cf. Fig. 1 IB). This arrangement may then be flipped over (or the laser welding position has to flip) and may be arranged on the flange 2 with an integral second contact member 7 and on the first (separate) electrical contact member 5 as indicated in Fig. 11C. Finally, the electrically insulating member 3 is welded to the flange 2 via weld seam 4 and to the contact members 5, 7 via weld seams 6, 8 (cf. Fig. 1 ID). The ring member 9 may be made of materials described herein with respect to the flange 2 and electrical contact members 5, 7.

[0100] Figs. 12 and 13 show yet another embodiment of an electrical feedthrough 1 according to the present invention which is a modification of the embodiment shown in Figs. 9 and 10, wherein here both electrical contact members 5, 7 are separate with respect to the flange 2 and are welded to a side of the electrically insulating member 3 to which also the ring

[0101] 23.137P-WO | 03.11.2025 member 9 is welded, whereas the flange 2 is welded to the opposite side of the electrically insulating member 3.

[0102] Fig. 14 shows a schematic illustration of an application of an electrical feedthrough 1 according to the present invention which may be used to separate electrical implant housing potentials (dipole design). Particularly, Fig. 14 shows an assembly 100, e.g. an implantable medical device 100, comprising a first electrical feedthrough 1 according to the invention (e.g. as shown in Figs. 9 to 10) and a second electrical feedthrough 1’ according to the invention (e.g. as shown in Figs. 9 to 10) wherein the assembly 100 further comprises a first battery and an opposing second battery and an intermediary housing 109 arranged between and connected to the first and the second electrical feedthrough 1, 1’, wherein the assembly 100 further comprises an electronic module 108 accommodated in an interior space 109a of the intermediary housing 109, and wherein the first electrical feedthrough 1 is connected to a housing 102 of the first battery and the second electrical feedthrough 1 ’ is connected to a housing 103 of the second battery. Thus, the assembly 100 shown in Fig. 14 may have two potentials associated with the housings 102, 103 that are separated by the intermediary housing 109 and thus form a comparatively long sensing vector 101 that can be used for signal sensing. Here particularly, the electrical feedthroughs 1, 1’ are used as battery lids in both cases. The electrical contact members 5, 7 of the feedthroughs / lids 1, 1’ can be connected to the module 108 via e.g. spring contacts 105, 107, 104, 106 or other suitable connectors. The intermediary housing 109 may formed by titanium or titanium allow, or a glass.

[0103] Fig. 15 shows a variant of the embodiment shown in Fig. 14, wherein here the second electrical feedthrough 1’ itself acts as the second electrical sensing potential spanning a sensing vector 1 to the battery housing 102. At the same time an antenna 13 may be integrated into the second feedthrough 1 ’ and can ensure wireless communication since the electrically insulating member 3 is RF transparent, in particular (e.g. due to being formed out of a glass or other suitable material).

[0104] Fig. 16 and 18 show further embodiments of an electrical feedthrough 1 according to the present invention, wherein particularly the flange 2 forms a battery lid 1. Typically, when

[0105] 23.137P-WO | 03.11.2025 producing a battery, an electrolyte has to be filled into an interior space of a housing 10 of the battery. A corresponding through-hole 50 serving as a filling hole has to be hermetically sealed afterwards. Particularly, here, the through-hole 50 is integrated into one of the electrical contact members 5, 7 (e.g. into the first contact member 5 as shown in Figs. 16 to 18). As indicated in Fig. 18, the respective electrical contact member 5, 7 may have a protrusions or recessed features to enable filling and closing by means of laser welding.

[0106] Furthermore, Figs. 19 and 20 show further embodiments of an electrical feedthrough 1 according to the present invention, wherein here the electrical contact members 5, 7 also comprise protrusions (pins, one- or double-sided). Typically, batteries have pins in implants. By choosing this design variant a drop-in replacement may be realized, if the connection mechanism requires pins. The flange 2 designed as a lid may comprise a mounting rim 2c to simplify the assembly. Particularly, according to Fig. 19, the first electrical contact member 5 comprises a flat first base 500 and a first feedthrough pin 501 protruding outwards from the first base 500. In the same fashion, the second electrical contact member 7 comprises a second flat base 700 and a second feedthrough pin 701 protruding outwards from the base 700. In contrast thereto, the feedthrough pins 501, 701 of the embodiment shown in Fig. 20 protrude in both directions from the respective base 500, 700, i.e., outwards as well as into the interior space 10a of the housing 10.

[0107] Furthermore, Fig. 21 shows a further aspect of the present invention suitable for a sensor application. Particularly, the amorphous structure of the glass and the linear elastic deformation behavior make the electrically insulating (e.g. glass) member 3 a suitable substrate to carry a strain gauge track 12. The conductive track 12 may be applied by vapor deposition of metal materials such as titanium, copper, gold, niobium, iridium and alike. Alternatively, the conductive track 12 may be applied by chemical galvanic deposition or by additive manufacturing methods like FDM (fused deposition modeling), BJ (Hinder jetting) or NPJ (nano particle jetting). To enhance the hermetic laser welding result between the electrically insulating (e.g. glass) member 3 and the metal layer (i.e. flange 2), vapor deposited coupling metals such as titanium or niobium may be deposited on the glass in the same way as the conductive tracks 12 for the sensor. Connected to an electronic circuitry board and an IC, resistance measurements may be performed, e.g., to determine the

[0108] 23.137P-WO | 03.11.2025 environmental blood pressure of the patient. Particularly, Fig. 26 shows the connection of such a sensor to an implant housing 10. It may be hermetically sealed by means of laser welding.

[0109] Figs. 23 and 24 show yet another aspect of the present invention, wherein here the conductive track 13 acts as an antenna or coil ensuring wireless communication. There may be one or more contacting points 13a, 13b via which the track may be electrically contacted.

[0110] Furthermore, Figs. 25, 26 and 27 show a combination of both functionalities, the electrical feedthrough 1 and the sensor / antenna / coil functionality provided by the respective conductive track 12, 13. Fig. 25 and 26 show a battery lid 1 with integrated sensor functionality provided by conductive track 12 to measure the internal battery pressure / battery swelling. This can be used as an additional factor to determine the end of service of the battery.

[0111] Furthermore, Fig. 27 shows an embodiment of the electrical feedthrough 1 according to the present invention that may substitute a header as usually used on implants such as cardiac pacemakers completely. Particularly, the electrical feedthrough 1 provides electrical contact members 5, 7 that can be used to measure electro cardiac signals. These electrodes may be especially coated with a surface increasing coating like fractal iridium or titanium nitrite, deposited using a vapor deposition process to enhance the signals. The antenna 13 arranged on the electrically insulating member 3 (e.g. glass member 3) provides wireless communication of / with the implant.

[0112] The solutions according to the present invention combine several advantages. The waferlike production process of the various electrical feedthroughs according to the invention facilitate the production of large quantities at low costs. The presented method of manufacture can create different customized types of electrical feedthroughs out of the same wafer. Fast in-production-line adaption is possible with laser trimming of the resistance traces. The method further allows in-line-calibration, and the trimming does not need to be made by the IC. Due to employing laser welding technology, vacuum and brazing processes can be omitted. Particularly, expensive gold braze is not needed for the hermetic seal om

[0113] 23.137P-WO | 03.11.2025 contrast to standard ceramic feedthroughs. Furthermore, expensive pin materials, as well as ceramics, ceramic coatings, and flange milling is not needed, too. The present invention allows the manufacture of very small feedthroughs. As the handling of small parts like gold braze rings and pins is not necessary, the method according to the present invention is highly automatable.

[0114] 23.137P-WO | 03.11.2025

Claims

- 23 -Claims1. An electrical feedthrough (1), comprising: a metallic flange (2) comprising a first side (2a), a flat electrically insulating member (3) being transparent to laser light (L), the electrically insulating member (3) comprising an outer circumferential edge region (30) being arranged on the first side (2a) of the flange (2), wherein the outer edge region (30) is hermetically joined to the first side (2a) by a first weld seam (4), and wherein the electrically insulating member (3) comprises a first through-hole (31) delimited by a first inner circumferential edge region (310), and a first electrical contact member (5), the first electrical contact member comprising a first side (5a) being arranged at the first inner edge region (310) of the at least one first through-hole (31) and hermetically joined to the first inner edge region (310) of the at least one first through-hole by a second weld seam (6, 8).

2. The electrical feedthrough according to claim 1, wherein the electrically insulating member (3) comprises a second through hole (32) delimited by a second inner edge region (320), and the electrical feedthrough (1) comprises a second electrical contact member (7), the second electrical contact member (7) comprising a first side (7a) being arranged at and hermetically joined to the second inner edge region (320) by a third weld seam (8).

3. The electrical feedthrough according to claim 2, wherein the second electrical contact member (7) is integrally connected to the flange (2).

4. The electrical feedthrough according to one of the preceding claims, wherein the first weld seam (4), the second welding seam (6) and / or the third weld seam (8) is a laser- welded weld seam.23.137P-WO | 03.11.20255. The electrical feedthrough according to one of the preceding claims, wherein the flange (2) comprises an outside facing away from an interior of a housing (10) when the electrical feedthrough (1) is connected to the housing (10) via the flange (2), wherein said outside is formed by the first side (2a) of the flange (2) or faces away from the first side (2a).

6. The electrical feedthrough according to claim 3 or according to one of the claims 4 to 5 insofar referring to claim 3, wherein the electrical contact members (5, 7) and the flange (2) are arranged on the same side of the electrically insulating member (3), or wherein the electrical contact members (5, 7) and the flange (2) are arranged on different sides of the electrically insulating member (3).

7. The electrical feedthrough according to one of the preceding claims, wherein the electrical feedthrough (1) comprises a ring member (9), wherein the electrically insulating member (3) is arranged between the ring member (9) and the flange (2), and wherein particularly the ring member (9) extends further outwards in the radial direction of the ring member (9) than the weld seam (4) that connects the electrically insulating member (3) to the flange (2).

8. The electrical feedthrough according to one of the preceding clams, wherein the first electrical contact member (5) comprises a through-hole (50) for filling in a liquid.

9. The electrical feedthrough according to one of the preceding claims, wherein the first electrical contact member (5) is a first flat electrical contact member or comprises a flat first base (500) and a first feedthrough pin (501) protruding from the first base (500), and / or wherein the second electrical contact member (7) is a second flat electrical contact member or comprises a second flat base (700) and a second feedthrough pin (701) protruding from the second flat base (700).

10. The electrical feedthrough according to one of the preceding claims, wherein an electrically conductive track (12) for a pressure sensor is arranged on the electrically insulating member (3).23.137P-WO | 03.11.202511. The electrical feedthrough according to one of the preceding claims, wherein a planar communication coil (13) is arranged on the electrically insulating member (3).

12. A device (100), particularly an implantable medical device or a battery, comprising a housing (10) and an electrical feedthrough (1) according to one of the preceding claims having a flange (2) being connected to the housing (10).

13. A device (100), particularly an implantable medical device, comprising a first electrical feedthrough (1) according to one of the preceding claims and a second electrical feedthrough (T) according to one of the preceding claims, wherein the device (100) further comprises a first battery and an intermediary housing (109) arranged between and connected to the first and the second electrical feedthrough (1, 1’), wherein the device (100) further comprises an electronic module (108) accommodated in an interior space (109a) of the intermediary housing (109), and wherein the first electrical feedthrough (1) is connected to a housing (102) of the first battery, wherein particularly the intermediary housing (109) is electrically insulated from the housing (102) the first battery by the first electrical feedthrough (1).

14. The device according to claim 13, wherein the assembly comprises a second battery, and the second electrical feedthrough (T) is connected to a housing (103) of the second battery, wherein particularly the intermediary housing (109) is electrically insulated from the housing (103) of the second battery.

15. A method for producing an electrical feedthrough, particularly an electrical feedthrough according to one of the claims 1 to 11, wherein the method comprises- providing a flat metallic flange (2) comprising a first side (2a),- providing a flat electrically insulating member (3) being transparent to laser light (L), the electrically insulating member (3) comprising a circumferential outer edge region (30) and at least a first through-hole (31) delimited by a first inner circumferential edge region (310),23.137P-WO | 03.11.2025- 26 - providing at least a first electrical contact member (5), the at least one first electrical contact member (5) comprising a first side (5a), arranging the electrically insulating member (3) with its outer edge region (30) on the first side (2a) of the flange (2), and generating a weld seam (4) by laser- welding the outer edge region (30) to the first side (2a) of the flange (2), wherein laser light (L) applied to the electrically insulating member (3) and flange (2) upon laser welding travels through the electrically insulating member (3) before impinging on the first side (2a) of the flange (2), arranging the electrically insulating member (3) with its first inner edge region (310) of the at least one through-hole (31) at the first side (5a) of the at least one first electrical contact member (5), and generating a weld seam (6) by laser- welding the first inner edge region (310) of the at least one first through-hole (31) of the electrically insulating member (3) to the first side (5a) of the at least one first electrical contact member (5), wherein laser light applied to the electrically insulating member (3) and the at least one first electrical contact member (5) upon laser welding travels through the electrically insulating member (3) before impinging on the first side (5a) of the at least one first electrical contact member (5).23.137P-WO | 03.11.2025

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