Patent ID: 12237104

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIGS.1A and1Bshow a magnetic-component module100with a core110, winding(s)120, a header130, and a substrate140such as a printed circuit board (PCB).FIG.1Bis a cross-section view of the magnetic-component module100, andFIG.1Ais a plan view of the header130that can be made by overmolding the core110. InFIG.1A, the outline of the core110is shown by the dashed lines. The magnetic-component module100can be a transformer with primary and secondary windings that extend around the core110, as shown inFIG.1. AlthoughFIG.1shows a transformer with two windings, other magnetic components can also be used, including, for example, an inductor with a single winding or a transformer with three or more windings. Circuitry components150and/or connectors can be located on the bottom surface of the substrate140. As shown inFIG.1, the magnetic-component module100can include surface-mount (SM) pins160that can also be located on the bottom surface of the substrate140. The circuitry components150can include passive components, such as, capacitors, resistors, etc. and can include active components, such as transistors. AlthoughFIG.1Bshows a substrate140with no internal layers, it is also possible to use a multilayer substrate.

The header130isolates the core110from the windings120and protects against short circuiting. Windings120extend around the core110and are defined by traces located on the outer surface of the header130and located in vias135extending through the header130. The traces defining the windings120can be provided by plating, vapor deposition, or any other suitable process. Wire bonds170can be used to connect the traces on the header130to pads on the substrate140. InFIG.1, the tops and bottoms of the windings120are defined by the traces that extend around the core110. But other arrangements are also possible. For example, the tops of the windings120can be defined by traces on the header130, and the bottoms of the windings120can be defined by traces on or in the substrate140. The traces in the substrate140can be connected to the traces on the header130by the wire bonds170and/or by including surface-mount pads (not shown) on the header130.

The header130can include an outer ledge and an inner ledge. The vias135can be included in the outer and inner ledge. The vias135can be arranged in one or more rows in the outer and the inner ledges. The center of the header130can include a conductive pad that extends from the inner ledge and that can be used to place and mount the header130to a surface-mount pad145on the substrate140. The conductive pad on the header130can be soldered to the surface-mount pad145on the substrate140. Other possible arrangements to mount the header130to the substrate140can also be used.

FIG.1also shows that the header130and wire bonds170can be overmolded with an overmold material180to stabilize and protect the components of the magnetic-component module100. Instead of overmolding, it is also possible to use a potting method or an encapsulation method to stabilize and protect the components of the magnetic-component module100.

FIGS.2A and2Bshow another magnetic-component module200with a core210, winding(s) defined by traces220and wire bonds270, a header230, and a substrate240.FIG.2Bis a sectional view of a magnetic-component module200with a header230, andFIG.2Ashows a plan view of the header230. InFIG.2A, the outline of a core210is represented by the dashed lines. The header230isolates the core210from the windings and protects against short circuiting. As shown inFIG.2B, circuitry components250and/or connectors can be located on the bottom surface of a substrate240. LikeFIG.1,FIG.2also shows that the header230and wire bonds270can be overmolded with overmold material280. AlthoughFIG.2Bshows a substrate240with no internal layers, it is also possible to use a multilayer substrate.

Windings extend around the core210. The windings are defined by traces220located on the outer surface of the header230and by wire bonds270extending over the core230and traces220located on or in the substrate240. The header230inFIG.2does not include any vias that extend through the header230. The traces220on the header230can define a winding separate from the winding defined by the wire bonds270and the traces on or in the substrate240. Alternatively, the traces220on the header230, the wire bonds270, and the traces on or in the substrate240can define a single winding. Furthermore, the direction of the windings defined by the traces220can be the same or different than the windings defined by the wire bonds270.

The header230can include outer ledges235.FIG.2Ashows four outer ledges235, but any number of outer ledges can be used. A continuous outer ledge could be used but would require longer traces on the header230and more room to attach the wire bonds270to the substrate240. Wire bonds275can be bonded to the outer ledges235to connect the traces220on header230to a pad or traces247on the substrate240. The outer ledges235can also provide a location to connect the wire bonds270of the windings with the traces220of the windings. The interior of the header230can include a platform234attached to the header230by two arms232. The two arms232can be arranged and the platform234can be designed small enough to allow the wire bonds270of the windings to be bonded in the interior of the header230. The platform234can be used for pick-and-place placement. The platform234can include a conductive pad that can be used to surface mount the header230to the substrate240. The conductive pad of the header230can be soldered to the substrate240. Other possible arrangements to mount the header230to the substrate240can also be used.

The wire bonds270can be terminated in a single row or multiple rows. As shown inFIG.2A, the wire bonds270can be terminated to the substrate240in single rows in the exterior and the interior of the core230. Other arrangements are also possible. For example, the wired bonds270can be terminated to the substrate240in two or more rows in the exterior of the core210and/or can be terminated to the substrate240in two or more rows in the interior of the core210.

FIG.3is a sectional view of the magnetic-component module300with a header330overmolding a core310where the magnetic-component module300includes conductive pads390that can electrically connect the header330directly to surface-mount pads on a host substrate (not shown) without any additional connection wires. The header330can be made by overmolding the core310and includes vias335arranged around the exterior and the interior of the core310. Circuitry components350can be located on the top surface of a substrate340.FIG.3also shows that the header330and wire bonds370connecting the header310to the substrate340can be overmolded with overmold material380. AlthoughFIG.3shows a substrate340with no internal layers, it is also possible to use a multilayer substrate.

Similar to that shown inFIG.2, windings extend around the core310and are defined by traces located on the outer surface of the header330and located in the vias335extending through the header310. As shown inFIG.3, wire bonds370can connect the traces on the header330and the substrate340. Instead of or in addition to the wire bonds370, an outer edge portion of the header330can include a conductive pad that is connected to a corresponding surface-mount pad345on the substrate340. The header330can also include another pad or pads that can be connected to the host substrate. Alternatively, the header330can be shaped to engage with a corresponding connector on the host substrate.

FIGS.4-13show steps of a method of manufacturing the magnetic-component module100shown inFIG.1.FIG.4shows providing the ring core110.FIG.5shows that the ring core110can be overmolded with a resin to form the header130.FIG.6shows that the header130can be plated on top and bottom to form traces for the windings120.FIG.7shows that the substrate140, such as a PCB, can be provided with traces and the surface-mount pad145on outer surfaces according to conventional techniques.FIG.8shows that the header130can be mounted by adhering or soldering the header130into place on the substrate140.FIG.9shows that the wire bonds170can be formed between the header130and the substrate140.FIG.10shows that an overmold material180can be overmolded to cover or encapsulate the header130and the wire bonds170on one side of the substrate140.FIG.11shows that solder147can be deposited on the substrate140on the opposite surface to the overmold material180.FIG.12shows that the components150and the I/O pins160can be mounted on the substrate140using the solder147.FIG.13shows the finished magnetic-component module100shown inFIG.1.

The magnetic component module200can be made in a similar manner, except that the header provided inFIG.5can include no vias, the substrate provided inFIG.6can have traces to define the windings, and additional wire bonding can be provided inFIG.9provides wire bonds270to define the windings.

As described above with respect toFIG.3, the magnetic-component module300includes conductive pads390that can electrically connect the header330directly to surface-mount pads on a host substrate (not shown) without any additional connection wires.FIGS.14-22show steps of a method of manufacturing the magnetic-component module300shown inFIG.3.FIG.14shows providing the ring core310.FIG.15shows that the ring core310can be overmolded with a resin to form the header330.FIG.16shows that the header330can be plated on top and bottom surfaces to form traces for the windings320and form the conductive pad390.FIG.17shows that the substrate340, such as a PCB, can be provided with traces and the surface-mount pad345on outer surfaces according to conventional techniques.FIG.18shows that the header330can be mounted by adhering or soldering the header330into place on the substrate340.FIG.19shows that the wire bonds370can be formed between the header330and the substrate340.FIG.20shows that an overmold material380can be overmolded to cover or encapsulate the header330and the wire bonds370on one side of the substrate340, while leaving the conductive pad390exposed.FIG.21shows that solder347can be deposited on the substrate340on the opposite surface to the overmold material380.FIG.22shows that the components350can be mounted on the substrate340using the solder347.

FIG.23is a block diagram of an example of an implementation of a magnetic-component module TXM. InFIG.23, the magnetic-component module TXM is implemented as an isolated converter with the dashed line through the transformer TX showing the isolation boundary. The primary side that is on the left side ofFIG.23and that is connected to the primary winding PR is isolated from the secondary side that is on the right side ofFIG.23and that is connected to the secondary winding SEC. For example,FIG.23shows that the electronic module TXM can include a switching stage SS, a control stage CS, a transformer TX, a rectifier stage RS, and an output filter LC. The transformer TX can include the core and windings that are defined by wire bonds and traces as previously described. The circuitry and components other than the transformer TX can include other electronic components that are attached to the substrate or PCB on which the transformer TX is mounted, as previously described.

As shown inFIG.23, the switching stage SS receives an input voltage Vin and outputs a voltage SSout to at least one primary winding PRI of the transformer TX. The switching stage can include switches or transistors that control the flow of power. The control stage CS includes an input control signal CSin. The control stage CS can control the switching of the switches in the switching stage SS and can monitor the transformer TX via an auxiliary winding AUX. The dotted vertical line through the transformer TX represents the galvanic isolation between the primary winding PRI and the auxiliary winding AUX from the secondary winding SEC. The secondary winding of the transformer TX can be connected to a rectifier stage RS that in turn is connected to an output filter LC that outputs a DC voltage between +Vout and −Vout. The rectifier stage can include diodes and/or synchronous rectifiers that rectify the voltage at the secondary winding SEC. The output filter LC can include an arrangement of inductor(s) and capacitor(s) to filter unwanted frequencies.

FIG.24is a block diagram of a gate-drive-circuit application that can include one or more of the magnetic-component modules TXM shown inFIG.23. The vertical and horizontal dotted lines represent galvanic isolation.FIG.24shows that the magnetic-component modules TXM can include, for example, a +12 Vdc input and −5 Vdc and +18 Vdc outputs, which could be used, for example, to drive metal-oxide-semiconductor field-effect transistor (MOSFETs) or insulated-gate bipolar transistors (IGBTs). The outputs of the magnetic-component modules TXM can be connected to gate driver IXDD614YI. A controller CONT can transmit and receive control signals represented by those control signals shown in the dotted-line boxes, including, for example, power-supply disable, pulse-width modulation PWM enable, low-side and high-side PWM, over-current detection, etc. The control signals can be transmitted and received between the controller CONT and the isolation circuitry ISO and between the controller CONT and the magnetic-component modules TXM. The isolation circuitry ISO can receive and transmit feedback signals VDSMeasure. The isolation circuitry can include a transformer, a capacitor, an opto-coupler, a digital isolator, and the like. The output of the gate drive circuit can be connected to a gate of a switch located in an inverter-unit circuitry as a portion of an inverter for a motor control application as shown inFIG.25.

FIG.25shows circuitry for a motor control application that can include a power supply PS running at a fixed frequency of 50 Hz or 60 Hz, for example, an inverter INV, and a motor MTR running at its required frequency. As shown, the inverter INV can include a power converter PC, a smoothing circuit S, and inverter unit circuitry IU controlled with PWM control.FIG.25shows that a controller CONT can be included to control the gate drive units GDU ofFIG.24. The gate drive units GDU can control the gates of the switches within the inverter unit circuitry IU. Feedback FB can be provided to the controller CONT from the motor MTR to stabilize control of the gate drive units GDU.

A package including the magnetic-component module can be any size. For example, the package can be about 12.7 mm by about 10.4 mm by about 4.36 mm. A package with these dimensions can provide higher isolation. The magnetic-component module can be used in many different applications, including, for example, industrial, medical, and automotive applications. For example, as explained above, the magnetic-component module can be included in a gate drive. The magnetic-component module can provide 1 W-2 W of power with an efficiency of greater than 80% and can provide 3 kV or 5 kV breakdown rating depending on the footprint of the magnetic-component module, for example. The magnetic-component module can include UL-required reinforced isolation and can operate at temperatures between about −40° C. and about 105° C. or between about −40° C. and about 125° C., for example. The magnetic-component module can have a moisture sensitivity level (MSL) of 1 or 2, for example, depending on the application. The magnetic component module can be used in battery management systems or programmable logic controller and data acquisition and communication compliant with RS484/232.

If the magnetic-component module includes a transformer, then, for example, the primary winding can include at least 20 turns and the secondary winding can include 12 turns. The coupling factor of the transformer can be 0.99, for example. The primary windings can have a direct-current resistance (DCR) of about 17.8 Ω/turn, and the secondary windings can have DCR of about 16.9 Ω/turn, for example. The maximum current can be 600 mA (over-current protection) with typical current being 300 mA, for example, to ensure that the magnetic-component module is not damaged in such over-current situations. The core can have an inner diameter of about 5.4 mm, an outer diameter of about 8.8 mm, and a height of about 1.97 mm, for example. The spacer can have an inner diameter of about 5.1 mm, an outer diameter of about 8.8 mm, and a height of about 0.2 mm, for example. The transformer can have size of about 12.7 mm by about 10.4 mm by about 2.5 mm, for example. The core can be made of any suitable material, including, for example, Mn—Zn, Ni—Zn, FeNi, and the like. The spacer can be made of any suitable material, including, for example, an epoxy adhesive. The wire bonds can be made of any suitable material, including, for example, Al or Cu. The pins can be made of any suitable material, including, for example, Cu with Ni—Sn coating. The overmold material can be made of any suitable material, including, for example, epoxy resin.

It should be understood that the foregoing description is only illustrative of the present invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the present invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications, and variances that fall within the scope of the appended claims.