Recipient

Abstract

Receiver (1), in particular implantable receiver (1) for transmitting energy to an implant, with - a multilayer circuit board comprising a plurality of electrically conductive layers (11 - 16), - wherein the circuit board comprises an outer coil area and a multilayer inner area enclosed by the coil area, - a coil which is integrally incorporated at least partially in the layers (11 - 16) of the circuit board in the coil area, - where within this inner area the number of layers (11 - 16) of the circuit board is lower than in the coil area.

Description

Field of invention

[0001] The invention relates to a receiver, in particular an implantable receiver for transmitting energy to an implant, an implantable system and a method for manufacturing a receiver. State of the art

[0002] Implantable receivers for implants, which have a coil for receiving energy or signals, are known from the prior art. In known receivers, a copper magnet wire coil is soldered and glued onto the circuit board. Typically, due to the size and number of electrical components, two circuit boards are required, which must be manually stacked on top of each other and connected with pins. This involves many assembly steps, which are also prone to errors.

[0003] US Patent 8,521,303 B2 describes an exemplary implantable coil arrangement from the prior art. The planar coil shown therein is integrated into a polymer matrix and can comprise a large number of coil layers. However, the arrangement shown with the coil is comparatively large.

[0004] US patent 2013 / 0199027A1 describes another exemplary coil arrangement from the prior art, which can be used, among other things, for an implant. The coil arrangement shown there has a multilayered structure, whereby the structure of the coil arrangement can include a cavity. Disclosure of the invention

[0005] The object of the invention is to provide an improved receiver compared to the prior art and an improved method for manufacturing a receiver. In particular, the receiver should be more compact or less expensive to manufacture.

[0006] The problem is solved, for example, by a receiver according to claim 1 or by a method according to the dependent claim. Further developments of the method or the device are specified in the dependent claims.

[0007] A first aspect concerns a receiver, in particular an implantable receiver for transmitting energy to an implant, with a multilayer circuit board comprising a plurality of electrically conductive layers, wherein the circuit board comprises an outer coil area and a multilayer inner area enclosed by the coil area, a coil which is at least partially integrally incorporated in the layers of the circuit board in the coil area, wherein within this inner area the number of layers of the circuit board is less than in the coil area.

[0008] Another aspect concerns an implantable system with a receiver in one of the typical embodiments described herein and with an electromechanical implant.

[0009] Another aspect concerns a method for manufacturing a receiver, in particular implantable receivers for transmitting energy to an implant, which comprises a circuit board, with: manufacturing a multilayer base membrane of the circuit board with a plurality of layers, constructing further layers on a top and / or a bottom of the base membrane, wherein at least in some part of the further layers in the coil area windings of the coil are integrated, and creating an upper cavity or a lower cavity from the further layers in the inner area within the coil area by removing, e.g. milling or grinding out, the further layers in the inner area.

[0010] Recipients of these embodiments can be implanted, for example subcutaneously or near or on a bone.

[0011] Typically, one or more insulating layers are provided for each conductive layer. For example, conductive layers and insulating layers can alternate to form the circuit board structure. The bottom or top layer can be exposed or covered with another insulating layer.

[0012] Due to the larger number of layers in the coil area, an upper cavity is typically formed, which is bounded by an upper edge. The upper edge is typically formed, at least partially, by the additional layers in the coil area, which are located above a base diaphragm. The base diaphragm typically comprises the inner and outer areas. In typical embodiments, only the base diaphragm of the circuit board is present in the inner area, whereas in the coil area, additional layers may be formed above or even below the base diaphragm. The additional layers on the underside in the coil area typically form a lower edge.

[0013] Typically, the coil windings are formed within the coil area. This allows for a space-saving and protected arrangement of the windings in the layers within the coil area. In typical embodiments, between 3 and 15 windings per layer are provided, particularly between 5 and 10, or especially exactly 7 windings per layer. In typical embodiments, the coil area comprises three or more layers, for example, at least two layers of the base membrane or at least two further layers within the coil area. Typically, at least 3 or at least 4 layers are present in the base membrane or in the inner area. Typically, at most 6 or at most 10 layers are arranged in the base membrane or in the inner area. In typical embodiments, at least 8 or at least 12 further layers are arranged within the coil area.In typical embodiments, there are at most 16 additional layers or at most 25 additional layers in the coil area.

[0014] Typical receivers are suitable for electromechanical implants. Typical electromechanical implants are, in particular, distraction devices suitable, for example, for the treatment of long bones or scoliosis. Typically, the receiver is configured to provide energy for an electric drive motor of an active implant, for example, a power output of at least 0.1 watts or at least 0.5 watts. Typical embodiments are suitable for powering active implants, where "active" typically means that the implant can perform a movement or includes a drive motor.

[0015] In typical receiver manufacturing processes, the additional layers are applied both internally and in the coil area. A typical layer of the base diaphragm, or of the additional applied layers, comprises conductive traces or, typically, a conductive layer per layer.

[0016] In typical processes, an upper rim and the upper cavity are formed in the inner area by milling out the inner area of ​​the coil; in addition, a lower rim and the lower cavity can also be formed in the inner area on the underside.

[0017] Typically, the inner area comprises at most or less than half as many layers as the coil area. This creates an upper cavity and possibly also a lower cavity for accommodating electronic components.

[0018] In typical embodiments, the coil area on the upper side of the circuit board forms an upper board around the inner area, within which electronic components are arranged. Typically, the maximum height of the electronic components on the upper side is at most twice, typically at most 1.5, 1.2, or 1.1 times the height of the step between the coil area and the inner area on the upper side. This step corresponds to the height between the top of the base diaphragm and the upper edge of the upper board. These height limits typically apply analogously to electronic components arranged in a lower cavity (present in some embodiments) relative to the edge of the lower board. These height limits ensure protected mounting of the components and create a flat or uniform profile for the receiver.

[0019] In typical receivers, the coil area or the further layers of the coil area form a lower board on the underside of the circuit board, which surrounds a lower cavity in the inner area on the underside.

[0020] In some receiver designs, electronic components can be enclosed by the base membrane or the other layers of the coil area, or integrated into the layers, particularly of the base membrane, in the interior.

[0021] Typically, the circuit board is a single piece. In alternative designs, at least two circuit boards are provided, one of which may be specifically designated for the coil. Foldable, bonded rigid-flex constructions can be used. This arrangement creates a base membrane during the circuit board production process, with additional layers built up on the underside. In typical designs, only a lower cavity or no cavity is created initially. This makes the top side of the circuit board easier to populate. In addition to the internal area and the coil area, the circuit board also has a flexible section. After the electronic components have been mounted, another coil section can be folded over this flexible section and bonded in place. This design allows for a higher coil inductance or a higher current rating.Polyimide can be used as a material for the flexible area.

[0022] Typical receivers include a radio-waveless feedback device designed to generate feedback on the operating status of an implant connected to the receiver. The feedback device is typically located in the lower or upper cavity. It may also be enclosed by the base membrane or coil area, or integrated into the layers, particularly of the base membrane, within the implant.

[0023] A possible operating state could be the functionality of an implant connected to the receiver or a direction of movement of a drive of an implant connected to the receiver.

[0024] Typical receivers include a switch for changing the operating state of the implant connected to the receiver. Typical switches include: reed contacts, photodiodes, or electromechanical push-button switches. Typical switches operate without electromagnetic radiation and are therefore independent of radio wave transmission, for which the coil can typically be used.

[0025] In typical designs, either the upper or lower cavity is filled with a resin-hardener mixture. The upper or lower board in the coil area can serve as a mold. Typically, both cavities are filled.

[0026] Typical receivers are overmolded with a biocompatible material, such as silicone or epoxy resin. In some designs, a glass or ceramic housing is also possible, with the halves being bonded or welded together.

[0027] To minimize damage to the biocompatible material, the edges of the circuit board in certain receiver designs are radiused. This avoids sharp edges and facilitates implantation.

[0028] Typically, the inner area of ​​the base membrane is covered by a protective layer on at least one of its top and bottom surfaces during the build-up of subsequent layers. Typical protective layers include, for example, Teflon or are made of Teflon. The protective layer can be located within a prepreg or insulation layer that has a cutout in the inner surface.

[0029] For the production of the circuit board, known manufacturing processes from printed circuit board technology for the production of multilayer circuit boards can be used, which enable the integration of the coil into the circuit board or also enable the selective generation of height levels.

[0030] After the circuit board has been manufactured and, if necessary, the cavity(s) milled, solder paste is applied to the cavity in typical designs. This can be done, for example, by jet printing or dispensing.

[0031] Typical methods also include placing electronic components on the upper surface of the interior, pouring a resin-hardener mixture into the upper cavity, or overmolding the receiver with a biocompatible material.

[0032] Typically, the coil section contains at least 10 layers, typically at least 20 layers, or at least 24 layers. Typical embodiments comprise a maximum of 100 layers, typically a maximum of 50 layers. Typical coils comprise a minimum of 50 turns, a minimum of 100 turns, or a minimum of 160 turns. Typically, the coil comprises a maximum of 500 turns or a maximum of 200 turns.

[0033] Typical advantages of these embodiments include a compact design with, in some cases, significantly increased functionality or optimized efficiency compared to known active implant receivers. Typical receivers have a height of less than 5 mm or less than 4 mm. The step of the upper rim is typically at least 1 mm or at least 2 mm. Typical lower rim heights are a maximum of 1 mm or a maximum of 0.5 mm. Typical diameters are at least 15 mm or at least 20 mm, or at most 30 mm or at most 50 mm. The thickness of the base membrane is typically at least 5%, at least 7%, or at most 20% or at most 15% of the total receiver height.

[0034] Typical receiver designs allow for the integration of more functions. Soldering the coil can be avoided, for example, reducing the risk of reverse polarity.

[0035] Typical designs are more robust because fewer individual parts are used and both the coil as an integral component of the circuit board is better protected and the components within the cavities are better protected.

[0036] Typically, fewer assembly steps are required for these embodiments than for known receivers from the prior art, or the assembly can be carried out more cost-effectively. Brief description of the drawings

[0037] Further advantages and features of preferred embodiments of the invention are explained below with reference to the accompanying drawings, the figures showing: Fig. Figure 1 is a schematic sectional view of an embodiment of the invention; Fig. Figure 2 shows a further embodiment in a perspective, schematic view; and Fig. Figure 3 shows the process of a method according to the invention. Description of preferred embodiments

[0038] Typical embodiments are described below with reference to the figures, whereby the invention is not limited to the exemplary embodiments, but rather the scope of the invention is determined by the claims.

[0039] In the Fig. Figure 1 shows a receiver 1, which may be part of an implant system that may include an electromechanical implant (not shown in the figures) that can be connected to the receiver 1.

[0040] Receiver 1 is implantable and suitable for transmitting energy to the implant. For this purpose, receiver 1 comprises a coil capable of transmitting or receiving energy sufficient to power an electromechanical drive of an implant, e.g., an intramedullary nail as shown in DE 10 2011 053 638 A1, or a scoliosis treatment unit as shown in DE 10 2010 047 738 A1.

[0041] Receiver 1 is suitable for transmitting a continuous power output of at least 1W to an active or mechatronic implant.

[0042] Receiver 1 comprises a multilayer circuit board, which includes a base membrane 3 extending horizontally across the entire cross-section of the circuit board. The base membrane comprises four layers 11-14, which are designed as electrically conductive, structured copper layers.

[0043] In an outer coil area, the circuit board forms an upper board 17 with 15 additional upper layers 15 and a lower board 18 with 3 additional lower layers 16. For clarity, not all of the additional layers are labeled with a reference symbol.

[0044] Borders 17 and 18 each surround an inner area in which only the four layers 11 - 14 of the base membrane are present.

[0045] Between all layers 11-16, prepregs are arranged as insulating layers, with the outermost layers 11 and 14 being free in the interior to allow the placement of electronic components, which are shown by way of example with reference numerals 21 on the top side of the base membrane (layer 14) and on the bottom side of the base membrane (layer 11), or contacts 22.

[0046] In the coil area, layers 11-16, i.e., both layers 11-14 of the main diaphragm and the upper and lower layers 15 and 16, form coil windings of the coil. On each layer 11-16 there are seven (only schematically shown in the diagram). Fig. (1 shown) windings arranged. In this way, the coil is integrally integrated into the layers of the circuit board in the coil area.

[0047] In some embodiments, embedded parts can be integrated into the base membrane in the internal area. Furthermore, packaged or unpacked components, ICs, transistors, or resistors, for example, can be arranged there. Test points can be provided, particularly on the underside or top side, which can simplify testing the receiver before overmolding with silicone. Additionally, receivers of these embodiments can incorporate a ferrite sleeve around the coil area or a paste to improve the coil's efficiency.

[0048] In typical embodiments, the circuit board comprises printed circuit board materials known from the prior art, such as FR4 or polyimide.

[0049] An upper cavity is formed within the upper rim 17. A lower cavity is formed within the lower rim 18. The electronic components 21 of the illustrated embodiment do not project beyond the upper rim 17. This means that the electronic components 21 have a lower overall height than the height of the edge of the rim 17 above the surface of the top of the base membrane.

[0050] In various embodiments, the height of the rim can be defined as the height between the exposed layer or the uppermost or lowermost layer of the interior and the edge of the rim.

[0051] A piezo buzzer 26, arranged in the lower cavity, protrudes only 10% of the height of the lower rim above the exposed layer 11 of the underside of the base membrane. This creates a compact structure.

[0052] A nose 30 is provided on one side, which is formed from layers 11-14 of the base membrane and the lower additional layer 16. The nose 30 can be used with the exposed layer 14 for contacts, for example for connecting the implant.

[0053] The cavities formed by rims 17 and 18 are filled with a resin-hardener mixture. The entire receiver 1 is overmolded with silicone 32, making it biocompatible.

[0054] The Fig. Figure 2 shows another embodiment of a receiver 1 for supplying a mechatronic implant. The cavities of the receiver 1 of the Fig. Two of them have not yet been filled with resin-hardener mixture and the silicone layer is also missing.

[0055] In the perspective representation of the Fig. 2 it is clearly visible how the upper board 17 encloses an interior area in which electronic components 21 can be protected.

[0056] In typical designs, electronic components are arranged on the top, bottom, or both sides of the base membrane inside the membrane. This arrangement provides good protection against mechanical impacts.

[0057] The Fig. Figure 3 shows a typical process for manufacturing a receiver. The process starts in block 110, where a 4-layer base membrane is produced. Alternating structured layers of copper (cores) and insulating layers (prepregs) are applied and pressed together.

[0058] The base diaphragm consists of four copper layers and three insulating layers, which are structured, drilled, and electroplated. In the finished receiver, the top copper layer forms the layer on the upper side of the base diaphragm in the upper cavity, where the components are mounted. The test points are located on the bottom layer of the base diaphragm in the finished product.

[0059] In a block of 120, a prepreg milled in the interior, i.e. in the area of ​​the cavities, is placed on the base membrane on the top and bottom.

[0060] In block 130, Teflon discs are inserted into these milled recesses. Unlike the insulating material, these discs do not bond with the copper layer of the outermost layers of the base membrane.

[0061] In block 140, further layers and prepregs are applied as insulation material to the top and bottom of the base membrane. The outermost layer in each case is insulation material.

[0062] In block 150, a contour is milled into the resulting raw circuit board using a depth milling process that reaches down to the depth of the Teflon disc. This creates a cavity on both the top and bottom sides of the raw circuit board.

[0063] In block 160, the Teflon discs are removed from the raw circuit board.

[0064] In block 170, the surfaces of the cavities are finished with a thin layer of nickel (e.g. 3-10 nm) and a thinner layer of gold (approx. 0.5-3 nm).

[0065] In block 180, a solder paste is applied to the refined surfaces of the cavities, e.g. by jet printing or dispensing.

[0066] In block 190, the footprints, which are landing areas intended for components, are fitted with electronic components in the cavities.

[0067] In a block 200, the solder melts in the soldering oven, typically with vapor phase to achieve a uniform heat distribution, under the feet of the electronic components, whereby the components connect to the circuit board.

[0068] In block 210, the cavities are filled with a resin-hardener mixture until they are at least substantially level. Typically, no mold is used for this; the casting process is usually done without a mold.

[0069] In block 220, the resulting circuit board is overmolded with silicon to make the receiver biocompatible with the circuit board. This completes the process in the Fig. The 3 procedures shown have been completed.

Claims

[1] Receiver (1), in particular an implantable receiver (1) for transmitting energy to an implant, with - a multilayer circuit board comprising a plurality of electrically conductive layers (11 - 16), - wherein the circuit board comprises an outer coil area and a multilayer inner area enclosed by the coil area, - a coil which is integrally incorporated at least partially in the layers (11 - 16) of the circuit board in the coil area, - where within this inner area the number of layers (11 - 16) of the circuit board is lower than in the coil area. [2] Receiver (1) according to claim 1, wherein the inner area comprises at most half as many layers as the coil area. [3] Receiver (1) according to one of the preceding claims, wherein the coil area on a top side of the circuit board forms an upper board (17) around the inner area and wherein electronic components (21) are arranged in the inner area on the top side of the circuit board. [4] Receiver (1) according to one of the preceding claims, wherein on a bottom side of the circuit board the coil area forms a lower board (18) which surrounds a lower cavity in the interior on the underside. [5] Receiver (1) according to one of the preceding claims, wherein the circuit board is made in one piece. [6] Receiver (1) according to one of the preceding claims, comprising a radio waveless feedback device (26) which is configured to generate feedback about an operating state of an implant connected to the receiver (1). [7] Receiver (1) according to one of claims 4, 5 or 6, wherein the cavity or cavities are cast and / or an overmolding around the receiver (1) with a biocompatible material is provided. [8] Implantable system comprising a receiver (1) according to one of the preceding claims and an electromechanical implant. [9] Method for manufacturing a receiver (1), in particular an implantable receiver (1) for transmitting energy to an implant comprising a circuit board, comprising: - Manufacturing a multilayer base membrane of the circuit board with a plurality of layers (11-14); - Construction of further layers (15, 16) on a top and / or a bottom of the base membrane; - wherein at least in some of the further layers (15, 16) turns of a coil are integrated in a coil area; and - Creating an upper cavity or a lower cavity in the interior within the coil area by removing the further layers (15, 16) in the interior. [10] Method according to claim 9, wherein the inner area of ​​the base membrane on at least one of the top and bottom surfaces is covered by a protective layer during the construction of the further layers (15, 16). [11] The method of claim 9 or 10 further comprising: - Populating the interior on the top side with electronic components (21), - Pouring the upper cavity with a resin-hardener mixture, and / or - Overmolding the receiver (1) with a biocompatible material.

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