SMD inductor component with pin configuration

Abstract

Inductor component (100) in SMD package for low-frequency magnetic fields, comprising a housing (102) with a housing base (104) for mounting on a printed circuit board, three windings arranged within the housing (102), in particular essentially orthogonal to each other, along an X, Y and Z winding axis, a plurality of connection contacts (110) arranged on the housing base (104), and a pin configuration with at least two electrical interconnections (130, 132) permanently manufactured within the housing (102), wherein each of the electrical interconnections (130, 132) electrically connects two specific terminal contacts (110) and the terminal contacts (110) are assigned to the winding ends of the X, Y and Z windings, so that each winding can be electrically connected via the terminal contacts (110).

Description

[0001] The invention relates to an inductor component in SMD design for low-frequency magnetic fields, in particular for applications of contactless identification and / or near-field communication.

[0002] In the prior art, multi-axis inductor components are used, whose windings are arranged in a housing and connected to a printed circuit board via connection contacts located on the housing base. Marking features are commonly used for assembly and orientation, and geometric specifications, including aspect ratios of the housing base, position and size of the connection contacts, minimum distances in the pad layout, and limit values ​​for the flatness of the contact surfaces (coplanarity), are used for manufacturing and testing processes.

[0003] The assignment of winding ends to connection contacts, internal electrical connections between selected pins, and the corresponding test and measurement access points are often manufacturer-specific and differ between package types. Similarly, the geometric designs vary with regard to contact arrangement along the edges, contact grouping, and dimensional tolerances, which complicates the transferability of printed circuit board layouts and the standardization of assembly, inspection, and testing procedures.

[0004] It is an object of the invention to specify an inductor component in which the design of the pin configuration and / or the dimensions, including geometric specifications of the housing base area and the pad layout, are standardized and specified.

[0005] Accordingly, an SMD-mounted inductor component for low-frequency magnetic fields is proposed, comprising a housing with a base for mounting on a printed circuit board, three windings arranged within the housing, in particular substantially orthogonal to each other, along an X, Y and Z winding axis, a plurality of connection contacts arranged on the base of the housing, a pin configuration with at least two electrical interconnections fixed within the housing, wherein each of the electrical interconnections electrically connects two specific connection contacts and the connection contacts are assigned to the winding ends of the X, Y and Z windings, so that each winding can be electrically connected via the connection contacts, optionally with an assignment in which a first pin pair corresponds to connection pins 2 and 3 and a second pin pair corresponds to connection pins 6 and 7.

[0006] The housing can have a base area for mounting on a printed circuit board. Preferably, the design is suitable for SMD processes and supports automated pick-and-place. This makes assembly standardized and component placement reproducible. The base area preferably refers to the underside of the housing or a projected area of ​​this underside, which in particular comes into contact with solder pads on the printed circuit board.

[0007] Within the housing, three windings can be arranged along X, Y, and Z winding axes. In particular, the axes are essentially orthogonal to each other. This enables direction-independent field acquisition and separate measurement for each axis. The winding axis preferably refers to the direction of maximum magnetic coupling of the respective coil.

[0008] A multiple set of connection contacts can be provided on the housing base. For example, in a pad layout, the contacts are arranged along the edges and numbered. This makes the circuit board layout clear and the assignment of the winding ends unambiguous. Pad layout preferably refers to the spatial arrangement of the solder pads for the electrical connections.

[0009] The pin configuration can have at least two electrical interconnections within the housing. Preferably, each interconnection connects two specific terminal contacts. This creates a defined pairing and clearly defines the internal wiring. An interconnection preferably refers to a solid metallic connection between two pins inside the component.

[0010] The connection contacts can be assigned to the winding ends in such a way that each winding can be electrically connected via its assigned contacts. In particular, this allows for consistent testing and measurement access per axis. This simplifies commissioning and accelerates fault diagnosis.

[0011] In a preferred embodiment, it is proposed that a marking feature formed on the housing base can identify a reference connection contact. Preferably, the design is chosen as a dot marking that is assigned to a predetermined pin. This ensures unambiguous orientation during assembly and AOI, and avoids confusion. The marking feature preferably refers to a visible sign that identifies the position and reference pin.

[0012] The marking can indicate the assignment of the winding ends to the connection contacts. For example, the position of the dot makes the pin numbering traceable. This ensures consistency in the circuit diagram and pad layout, and makes the testing steps more structured.

[0013] Each electrical interconnection can be formed by a metallic connection located within the housing. Preferably, this is a fixed, conductive bridge that permanently connects two specific pins. This ensures stable internal wiring and unambiguous electrical pairing. A metallic connection preferably refers to a conductor integrated within the component that creates a low-resistance short circuit between two terminals.

[0014] Electrically interconnected connection contacts can be arranged along a common edge of the housing base. For example, the coupled pairs are placed on the same edge to optimize PCB layout. This reduces the trace length and minimizes crosstalk. A common edge preferably refers to an outer edge of the base along which multiple pads are aligned.

[0015] Preferably, electrically connected pairs can be arranged along opposite side edges. In particular, this results in a symmetrical pin configuration with clear lateral assignment. This simplifies handling during assembly and makes the test logic traceable.

[0016] In a preferred embodiment, it is proposed that the winding connection contacts can be configured as separate contact groups on the housing base. Preferably, each winding axis has its own group with a defined position. This ensures unambiguous assignment per axis and clear measurability. A contact group preferably refers to a set of pads assigned to a winding axis or a winding end.

[0017] Minimum distances may be specified between contact groups. For example, a greater distance is chosen between groups than within a group. This improves electrical decoupling and facilitates optical identification during inspection. Minimum distance preferably refers to the smallest permissible distance between two pad edges, as specified in the documentation.

[0018] In a preferred embodiment, it is proposed that the pin configuration be designed to be symmetrical about a central axis of the housing base. This preferably results in a balanced distribution of the connections on both sides. This makes the circuit board layout more organized and testing more systematic. The central axis preferably refers to an imaginary line through the base, with the left and right arrangements being mirror images of each other.

[0019] The pin configuration can be represented in a rectangular pad layout. For example, the pads are positioned along the edges of the base. This ensures unambiguous orientation and stable assembly. Pad layout preferably refers to the defined geometry and position of the solder pads.

[0020] Corner pads and / or side pads can be provided as options. Corner pads, in particular, serve as mechanical support points with a larger soldering surface. This improves the shear strength of the solder joints and reduces the tilting moment. Side pads are preferably pads located between two corners on an edge.

[0021] In a preferred embodiment, it is proposed that the connection contacts be numerically identified. Preferably, a sequential pin numbering system is used that is consistent in the documentation and manufacturing data. This ensures consistency in the circuit diagram and layout, and reduces the error rate during test setups. Pin numbering preferably refers to a fixed assignment of numbers to physical connection pads.

[0022] Each winding end can be uniquely assigned to a numbered terminal contact. For example, each axis receives a clearly defined contact pair or group. This simplifies measurement for each axis and speeds up commissioning. Axis assignment preferably refers to the fixed coupling between a winding axis and its set of associated pins.

[0023] In a preferred embodiment, it is proposed that at least one winding end can have electrically redundant contact via two connection contacts arranged on the housing base. Preferably, the same winding end is connected to two pins, so that an alternative connection is available. This increases contact reliability and reduces the impact of individual solder joint failures. Electrically redundant contact preferably refers to a double, functionally equivalent connection of the same electrical node to two physical pads.

[0024] Optionally, redundant contacting can be implemented as an internal short connection. For example, a metallic bridge within the housing directly connects both relevant pins. This minimizes contact resistance and ensures unambiguous internal pairing. A short connection preferably refers to a low-resistance, fixed connection between two terminal contacts.

[0025] In a preferred embodiment, it is proposed that a test scheme can be defined in which each of the X, Y, and Z windings can be controlled and / or measured via a predetermined combination of connection contacts. Preferably, the contact combinations are clearly documented and correspond to the pin numbering. This makes the test reproducible and the troubleshooting structured.

[0026] In particular, testing can be performed at a frequency of 125 kHz and under room temperature conditions of 25 ± 5 °C. For example, measuring instruments and test adapters are calibrated to these conditions. This improves comparability between production batches and simplifies calibration. A test scheme preferably refers to a defined sequence of measurement and control operations with associated contact combinations and operating conditions.

[0027] In a preferred embodiment, it is proposed that a first electrical short circuit can be provided between a first and a second terminal contact. Preferably, this is a fixed, low-resistance connection inside the housing. This ensures unambiguous pairing and low contact resistance. Short circuit preferably refers to a metallic bridge or internal conductor track that permanently connects two pins.

[0028] A second electrical short circuit can be provided between a third and a fourth connection contact. For example, the two short circuits are assigned to different contact groups. This supports the symmetry of the pin configuration and organizes the printed circuit board layout.

[0029] Preferably, the short connections can be implemented inside the housing. In particular, they are integrated into the internal wiring and are not visually visible. This makes the design more compact and simplifies external wiring.

[0030] In a preferred embodiment, it is proposed that the inductor component can be configured for operation at an excitation frequency of 125 kHz. Preferably, the winding configuration and contact combinations are adapted accordingly. This increases operational reliability in low-frequency applications and ensures consistent measurement conditions.

[0031] The assignment of the winding ends to the connection contacts can be defined accordingly. For example, each axis receives a defined contact group or pin pair. This simplifies testing for each axis and speeds up commissioning. Assignment preferably refers to the fixed coupling between a winding end and a specific set of pins.

[0032] In particular, operation is possible under operating conditions from -40 °C to +85 °C. Preferably, the material selection and housing design are adapted to this range. This supports reliable use in automotive and industrial environments. The operating temperature range preferably refers to the specified temperature range within which defined performance values ​​are maintained.

[0033] The pin configuration for each winding axis can also include an associated return conductor contact, arranged along a preferably opposite edge of the housing base. This assignment defines a closed current loop with a limited projected loop area for each axis. This reduces mutual interference between the axes and increases measurement stability. The return conductor routing can be specified in the documentation as a layout rule with a maximum permissible loop area per axis. Optionally, a minimum distance between return conductor contacts of different axes is specified to further reduce capacitive coupling.

[0034] As an example, the pin configuration includes a conductive shield segment arranged in close proximity to at least one contact group on an internal metal layer and electrically coupled to a reference contact (e.g., ground). A defined isolation distance is provided between the shield segment and the pads of the contact group. This reduces capacitive crosstalk effects between adjacent groups. The shield segment can be partially enclosing or designed as a straight shield tab. For manufacturing and quality assurance purposes, the isolation distance can be specified as a nominal dimension with a tolerance, for example, as a minimum distance relative to the pad edge.

[0035] At least one pin pair can be electrically coupled by an internal, fixed component that may have a predetermined characteristic value, such as a resistance value in the kiloohm range. This characteristic value serves to identify the pin configuration and / or axis assignment in automated test sequences. This allows the correct configuration to be recognized and documented without manual intervention. Different axes can be assigned different characteristic values, enabling multi-stage identification. The characteristic value and its tolerance range are specified in the bill of materials and the test plan.

[0036] Redundant pins on a winding axis can be equipped with contact surfaces that provide thermal decoupling from the circuit board, for example, through defined thermal pads with multiple narrow connections. This promotes uniform solder paste melting and reduces the risk of uneven solder distribution. Corner pads can have stronger thermal coupling than side pads to emphasize their mechanical support function. The thermal connection can be specified by geometric parameters (number, width, and length of the spreading arms) and noted in the manufacturing drawing.

[0037] In addition to the dot marking, a second marking element can be provided, such as a fine notch and / or a micro-symbol on a defined edge of the housing top. The combination of dot marking and second marking element is asymmetrical, so that a 180-degree rotation is clearly recognizable. This reduces the risk of misplacement in the line. The position and minimum dimensions of both marking elements can be specified, including a contrast criterion for optical inspection systems.

[0038] Each contact group can have a measurement window defined as a clear zone, allowing access for test probes and / or flying probe contacts. The measurement window preferably includes a minimum distance to adjacent pads and a minimum clearance area, which is specified in the documentation as a test access rule. This ensures reproducible contacting in serial testing, reduces setup times, and stabilizes test times. The measurement window can have different dimensions for each group to adapt to the respective position and density of the pads.

[0039] The described configurations can be implemented independently of one another. In some applications, a combination of return conductor routing, shield segment, and measurement window is advantageous because it addresses electrical decoupling, test accessibility, and process robustness simultaneously. In other applications, self-identification via resistor or ID bridges is preferred, for example, when multiple pin configuration variants are used on the same circuit board.

[0040] The following section explains embodiments, further developments, and examples of the invention in more detail with reference to the accompanying drawings. The figures show: Fig. Figure 1 shows an inductor component in SMD design in a top view with a housing; Fig. Figure 2 shows an SMD inductor component in a top view of the housing base without a housing cover; and Fig. Figure 3 shows a winding configuration for the X, Y, and Z winding axes.

[0041] Identical features are identified by the same reference numerals in the figures. The invention is further explained with reference to the two figures.

[0042] Fig. Figure 1 shows an inductor component 100 in SMD package with a housing 102 and a housing base 104 for mounting on a printed circuit board (not shown). A dot marking 106 is shown on a top side of the housing 102, which identifies a reference terminal contact and can indicate the assignment of the winding ends to the terminal contacts. The housing base 104 can be substantially rectangular and have a pad layout 108 along its edges with several terminal contacts 110 (consecutively also labelled 1-8).

[0043] Corner pads 112 can be arranged in the four corners; side pads 114 can be placed between them (see Fig. 2) be arranged. Within the housing 102, three windings can be arranged along an X, Y and Z winding axis, wherein the winding axes can in particular be substantially orthogonal to each other.

[0044] The pin configuration can comprise at least two electrical interconnections 130, 132 permanently installed within the housing 102, each interconnection being able to electrically connect two specific terminal contacts 110. The position of the terminal contacts 110 can be selected such that contact groups 116, 118, 120 are each assigned to an X, Y, or Z winding axis, respectively.

[0045] Contact group 116, assigned to the winding of the X-axis, can comprise terminal contacts 2, 3, 6, and 7 and be formed by electrical interconnections 130 (short connection 2-3) and 132 (short connection 6-7). Contact group 118, assigned to the winding of the Y-axis, can comprise terminal contacts 1 and 5. Contact group 120, assigned to the winding of the Z-axis, can comprise terminal contacts 4 and 8.

[0046] The dimensions of the housing base 104 and the connection contacts 110 can be configured for a low-profile design and a predetermined coplanarity of the connection contacts. Optionally, a coplanarity of no more than 0.10 mm is provided for an AOI-optimized version and no more than 0.15 mm for a standard version.

[0047] The pin configuration can be mirror-symmetrical relative to a central axis of the housing base 104 and can furthermore be represented in the rectangular pad layout 108. Furthermore, a numerical marking of the connection contacts 1-8 can be provided, which can uniquely assign each winding end to a numbered connection contact.

[0048] The marking 106 can be in a contrasting color and can serve for clear orientation during assembly and testing. The housing contour is shown with rounded corners. The side lengths of the rectangular housing base 104 can form a practical ratio, and the overall height of the housing 102 can be less than one of the side lengths of the housing base 104.

[0049] Furthermore, a type and date marking 122 may be present on the top side, which supports traceability.

[0050] Minimum distances can be provided between contact groups 116, 118, and 120, clarifying the spatial separation of the groups. For testing purposes, a test scheme can be provided in which each of the X, Y, and Z windings can be controlled or measured via a predetermined combination of connection contacts, preferably at a test / operating frequency of 125 kHz under room temperature conditions of 25 ± 5 °C. For operation, the inductor component 100 can be configured for an excitation frequency of 125 kHz and an operating temperature range of -40 °C to +85 °C.

[0051] Fig. Figure 2 shows the pad layout 108 of the inductor component 100 in a top view of the housing base 104 without the housing 102 or housing cover, showing the rectangular base shape and the connection contacts 110 arranged along the edges. The corner pads 112 with a larger projected soldering area, which can serve as mechanical support points, are shown in the four corners. The side pads 114 are arranged along each side.

[0052] The contact groups 116, 118, 120 can be assigned to the winding axes X, Y, Z and spatially separated from one another. Minimum distances can be provided between the contact groups 116, 118, 120. Within the contact groups, minimum cross-sectional areas of the connection contacts 110 on the housing base 104 can be maintained, and minimum distances can be provided between adjacent connection contacts 110 to facilitate the reflow process and AOI testability. The arrangement along the edges can be selected to ensure a unique orientation relative to a longitudinal axis 124 and a transverse axis 126 of the housing base 104. The dimensions of the pad layout 108 can accommodate aperture specifications for a solder paste stencil, whereby split or adapted opening geometries can be represented. The coplanarity of the connection contacts 110 preferably relates to the plane of the housing base 104.

[0053] The layout can support the assignment of the winding ends to the connection contacts 110, so that each winding axis can be electrically connected via its respective contact group. The spatial separation of the contact groups 116, 118, 120 preferably reduces crosstalk and facilitates measurement access per axis. The rectangular housing base 104 can be designed with an aspect ratio that allows for efficient placement in the printed circuit board design. The overall height of the housing 102 (not shown) can be specified in a dimensional tolerance table together with coplanarity and base area dimensions. The electrical interconnections 130, 132 can each run within the housing 102 and can be assigned to the paired connection contacts 2-3 and 6-7, respectively, with the connected pairs being arranged along opposite side edges of the housing base 104.Redundant contacting of at least one winding end can be provided via two connection contacts arranged on the housing base 104, optionally as internal short connections 130, 132. The numerical designation (1-8) of the connection contacts 110 and the axis assignment of the contact groups 116, 118, 120 are shown in the pad layout 108.

[0054] Fig. Figure 3 shows the electrical assignment of the contact groups 116, 118, 120 with regard to the winding configuration and the X, Y or Z winding axis.

[0055] The contact group 116 (X-winding) can be located at the right edge of the housing according to the top view and may include pins 2 / 3 and 6 / 7. In the electrical diagram, an inductance Lx can be routed between the short-connected pins 2-3 (interconnection 130, left winding end Lx) and the short-connected pins 6-7 (interconnection 132, right winding end Lx).

[0056] The contact group 118 (Y-winding) can be assigned to pins 1 and 5. An inductor Ly can be connected between pin 1 (left winding end Ly) and pin 5 (right winding end Ly), preferably without an internal short circuit.

[0057] The contact group 120 (Z-winding) can be assigned to pins 4 and 8. An inductance Lz can be connected between pin 4 (left winding end Lz) and pin 8 (right winding end Lz), preferably also without an internal short circuit.

[0058] This allows the X-winding to be contacted via the edge pairs (2 / 3) and (6 / 7) on the right, the Y-winding via individual pins 1 (top right) and 5 (bottom left), and the Z-winding via individual pins 4 (top left) and 8 (bottom right). The short connections 2-3 and 6-7 shown in the circuit diagram can be arranged in the layout according to... Fig.The two adjacent double pads on the right edge reflect the windings, while the Y and Z windings can each be diagonally connected via two single pads. A test scheme can provide that each winding can be controlled or measured via the defined combinations of the connection contacts 110, preferably at 125 kHz and 25 ± 5 °C. The design is suitable for operating conditions from -40 °C to +85 °C. REFERENCE MARK LIST 100 inductor components 102 cases 104 Housing footprint 106 Point marking 108 Pad Layout 110 Connection contact 112 Corner pad 114 side pad 116 Contact group X-winding (pins 2 / 3, 6 / 7) 118 Contact group Y-winding (pins 1, 5) 120 Contact group Z-winding (pins 4, 8) 122 Type / date marking 124 Longitudinal axis of the housing base 126 Transverse axis of the housing base 130 Interconnection / Short bandage Pins 2-3 132 Interconnection / Short bandage Pins 6-7

Claims

[1] SMD inductor component (100) for low-frequency magnetic fields, comprising a housing (102) with a housing base (104) for mounting on a printed circuit board, three windings arranged within the housing (102), in particular essentially orthogonal to each other, along an X, Y and Z winding axis, a plurality of connection contacts (110) arranged on the housing base (104), and a pin configuration with at least two electrical interconnections (130, 132) permanently manufactured within the housing (102), wherein each of the electrical interconnections (130, 132) electrically connects two specific connection contacts (110) and the connection contacts (110) are assigned to the winding ends of the X, Y and Z windings, so that each winding can be electrically connected via the connection contacts (110). [2] Inductor component according to paragraph 1, wherein a marking feature (106) formed on the housing base (104) identifies a reference terminal contact and indicates the assignment of the winding ends to the terminal contacts (110), optionally as a dot marking (106) to identify a predetermined pin. [3] Inductor component according to one of the preceding digits, wherein each electrical interconnection (130, 132) is formed by a metallic connection arranged inside the housing (102) and electrically interconnected connection contacts (110) are arranged along a common side edge of the housing base (104), preferably with electrically connected pairs along opposite side edges. [4] Inductor component according to one of the preceding digits, wherein the connection contacts (110) of the windings are formed as separate contact groups (116, 118, 120) on the housing base (104) and minimum distances are provided between the contact groups (116, 118, 120). [5] Inductor component according to one of the preceding digits, wherein the pin configuration is mirror-symmetrical relative to a central axis of the housing base (104) and is represented in a rectangular pad layout (108), optionally with corner pads (112) and / or side pads (114). [6] Inductor component according to one of the preceding digits, wherein a numerical identification (1-8) of the terminal contacts (110) is provided and a unique assignment of each winding end to a numbered terminal contact (110) is defined, preferably with a predetermined pin numbering and / or axis assignment. [7] Inductor component according to one of the preceding numbers, wherein at least one winding end has an electrically redundant contact via two connection contacts (110) arranged on the housing base (104), optionally as internal short connections (130, 132). [8] Inductor component according to any of the preceding digits, wherein a test scheme is defined in which each of the X, Y and Z windings can be controlled or measured via a predetermined combination of the connection contacts (110), preferably at a test / operating frequency of 125 kHz under room temperature conditions of 25 ± 5 °C. [9] Inductor component according to one of the preceding digits, wherein a first electrical short circuit (130) is provided between a first and a second terminal contact (110) and a second electrical short circuit (132) is provided between a third and a fourth terminal contact (110), preferably implemented with different short circuits (130, 132) inside the housing (102). [10] Inductor component according to one of the preceding digits, wherein the inductor component (100) is configured for operation with an excitation frequency of 125 kHz and the assignment of the winding ends to the connection contacts (110) is defined accordingly, preferably under operating conditions from -40 °C to +85 °C.

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