Integrated transformer module

Abstract

A module includes a substrate, a metal layer and an insulating layer laminated on the substrate, a bottom winding made of metal directly contacting the first metal layer or the second metal layer, a first insulating layer on the bottom winding, a magnetic core on the first insulating layer, a second insulating layer on the magnetic core, a top winding made of metal on the magnetic core and a part of the second insulating layer and directly contacting the first metal layer or the second metal layer, a third insulating layer on the top winding, and an electronic component on the third insulating layer, wherein a primary winding and a secondary winding of a transformer are defined by parts of the bottom winding and the top winding and are located on two sides of the magnetic core opposite to each other.

Description

Technical Field

[0001] This invention relates to transformers. More specifically, this invention relates to an integrated transformer module that can be used in DC-DC converters or power supply applications. Background Technology

[0002] Traditional power supplies and DC-DC converters require large discrete magnetic components, such as transformers and inductors, which have inherent losses, generate heat, emit electromagnetic interference (EMI), and are costly to manufacture. Battery-powered mobile phones and handheld applications require small, efficient, and cost-effective components.

[0003] Therefore, smaller magnetic components and transformers have been developed that are fabricated directly on substrates, such as printed circuit boards (PCBs) or silicon substrates. Components such as planar inductors have been fabricated as semiconductor chips on the surface of silicon substrates. These components have been made into something similar to integrated circuits (ICs) using semiconductor manufacturing techniques. However, as shown in, for example, U.S. Patent No. 10,244,633, in power management control ICs with passive components, the use of transformer windings defined by a metal-on-silicon layer cannot provide sufficient isolation in isolated DC-DC converters due to the small gaps between high-voltage components.

[0004] Furthermore, while circuit components and transformers can be built on the same silicon die, if high-capacitance capacitors, such as ceramic capacitors, are required, these components cannot be fitted onto the same silicon wafer. Therefore, large electronic components need to be located on a separate substrate from the silicon die and connected via space-consuming copper traces. Summary of the Invention

[0005] To overcome the above problems, a preferred embodiment of the present invention provides circuit modules, each including: a transformer integrated into a substrate, which can be connected to other components located on the same substrate and can be used in high-current DC-DC converter applications.

[0006] According to a preferred embodiment of the invention, a transformer in the module is manufactured using an electroplated metal layer located on a substrate. A module including a transformer with a magnetic core can be manufactured by: (1) a plating process different from conventional on-substrate transformer processes, (2) connecting the transformer to electronic components on and / or within the substrate, and (3) overmolding the electronic components with an insulating molding material. Overmolding the transformer and electronic components provides environmental friendliness and electrical isolation, making the module smaller than an unmolded module. Furthermore, the primary-side and secondary-side circuits of the transformer, coexisting on the silicon substrate, are electrically isolated from each other by a PN junction, which allows for a reduction or minimization of the distance between each circuit side.

[0007] According to a preferred embodiment of the present invention, a transformer module includes: a substrate; a plurality of metal layers and a plurality of insulating layers laminated on the substrate; a first bottom winding and a second bottom winding of the transformer made of metal, the first bottom winding being in direct contact with a first metal layer of the plurality of metal layers, and the second bottom winding being in direct contact with a second metal layer of the plurality of metal layers; a first insulating layer of the plurality of insulating layers located on the first bottom winding and the second bottom winding; a magnetic core located on the first insulating layer; a second insulating layer of the plurality of insulating layers located on the magnetic core; a first top winding and a second top winding of the transformer made of metal located on a portion of the magnetic core and the second insulating layer, the first top winding being in direct contact with the first metal layer of the plurality of metal layers, and the second top winding being in direct contact with the second metal layer of the plurality of metal layers; a third insulating layer of the plurality of insulating layers located on the first top winding and the second top winding; an electronic component located on the third insulating layer and connected to the transformer; and a molding material located on the electronic component. The first bottom winding and the first top winding are included in the primary winding of the transformer, and the second bottom winding and the second top winding are included in the secondary winding of the transformer. The primary winding and the secondary winding of the transformer are not electrically connected to each other.

[0008] The substrate may include silicon. The transformer module may also include circuitry located on the substrate, wherein the transformer and circuitry may be located on the same side of the substrate. The transformer may also include a PN junction in the substrate that isolates the primary and secondary sides of the transformer. The transformer module may also include input-output pads located on an opposite side of the substrate to the side of the substrate where the transformer is located. A top winding may extend above the surface on which the electronic components are mounted. The metal may be copper.

[0009] According to a preferred embodiment of the present invention, a method of manufacturing a transformer module includes: providing a substrate; forming a plurality of metal layers on the substrate; depositing metal to form a first bottom winding and a second bottom winding of the transformer, the first bottom winding being in direct contact with a first metal layer of the plurality of metal layers, and the second bottom winding being in direct contact with a second metal layer of the plurality of metal layers; forming a first insulating layer on the first bottom winding and the second bottom winding; electroplating a magnetic core on the first insulating layer; forming a second insulating layer on the magnetic core; depositing metal to form a first top winding and a second top winding of the transformer on the second insulating layer, the first top winding and the second top winding extending around the magnetic core, the first top winding being in direct contact with a first metal layer of the plurality of metal layers, and the second top winding being in direct contact with a second metal layer of the plurality of metal layers; forming a third insulating layer on the first top winding and the second top winding; mounting electronic components on the third insulating layer such that the electronic components are connected to the transformer; and overmolding the electronic components with a molding material. The first bottom winding and the first top winding are included in the primary winding of the transformer, and the second bottom winding and the second top winding are included in the secondary winding of the transformer. The primary winding and the secondary winding of the transformer are not electrically connected to each other.

[0010] The metal can be electroplated with copper.

[0011] According to a preferred embodiment of the present invention, a transformer module includes: a silicon substrate; circuitry located on a first side of the silicon substrate including input-output pads; a metallic bottom winding of the transformer located on a second side of the silicon substrate and in contact with the circuitry through the silicon substrate; a first insulating layer located on the bottom winding; a magnetic core located on the first insulating layer; a second insulating layer located on the magnetic core; a metallic top winding of the transformer extending around the magnetic core and a portion of the second insulating layer and in contact with the circuitry through the silicon substrate; a third insulating layer located on the top winding; electronic components located on the third insulating layer and connected to the transformer; and molding material located on the electronic components. The primary and secondary windings of the transformer are defined by portions of the bottom and top windings and are not electrically connected to each other.

[0012] The transformer may also include a PN junction in a silicon substrate that isolates the primary and secondary sides of the transformer. The metal may be copper.

[0013] According to a preferred embodiment of the present invention, a method of manufacturing a transformer module includes: providing a silicon substrate; forming a circuit on a first side of the silicon substrate including input-output pads; depositing metal on a second side of the silicon substrate to form a transformer bottom winding in contact with the circuit; forming a first insulating layer on the bottom winding; electroplating a magnetic core on the first insulating layer; forming a second insulating layer on the magnetic core; depositing metal on the second insulating layer to form a transformer top winding, the top winding extending around the magnetic core and in contact with the circuit through the silicon substrate; forming a third insulating layer on the top winding; mounting electronic components on the third insulating layer such that the electronic components are connected to the transformer; and overmolding the electronic components with a molding material. The primary and secondary windings of the transformer are defined by portions of the bottom and top windings and are not electrically connected to each other.

[0014] The metal can be electroplated with copper.

[0015] According to a preferred embodiment of the present invention, a transformer module includes: a silicon substrate; a circuit located on a first side of the silicon substrate; a metallic bottom winding of the transformer located on a second side of the silicon substrate and connected to the circuit; a first insulating layer located on the bottom winding; a magnetic core located on the first insulating layer; a second insulating layer located on the magnetic core; a metallic top winding of the transformer extending around a portion of the magnetic core and the second insulating layer and connected to the circuit; a third insulating layer covering the top winding; a lead frame having input-output pads connected to the transformer; and a molding material covering the silicon substrate, the transformer, and the lead frame except for the input-output pads. The primary and secondary windings of the transformer are defined by portions of the bottom and top windings and are not electrically connected to each other.

[0016] The transformer may also include a PN junction in a silicon substrate that isolates the primary and secondary sides of the transformer. The transformer module may also include wires connecting the transformer to a lead frame. The metal may be electroplated copper.

[0017] According to a preferred embodiment of the present invention, a circuit module includes: a redistribution layer comprising a metal layer, an insulating layer, and a magnetic component including a first metal winding extending around a magnetic core and connected to the metal layer; a substrate connected to a first side of the redistribution layer and including a first transistor and a second transistor; and an electronic component connected to a second side of the redistribution layer opposite to the first side. The first metal winding is thicker than the metal layer.

[0018] The substrate may include silicon and a PN junction between the first transistor and the second transistor. A portion of the first metal winding may extend beyond the surface of the redistribution layer. The substrate may include input-output pads located on an opposite side of the substrate to the side where the redistribution layer is located. The circuit module may also include a lead frame connected to the redistribution layer or the substrate. The circuit module may also include wires, wherein the lead frame may be connected to the substrate, and wherein the wires may be connected to both the lead frame and the redistribution layer. The magnetic component may be a transformer and may also include a second metal winding extending around a magnetic core. The first transistor may be connected to the first metal winding, and the second transistor may be connected to the second metal winding. The first metal winding and the second metal winding may be electrically isolated from each other. The magnetic component may be an inductor.

[0019] According to a preferred embodiment of the present invention, a transformer module includes: a substrate; an insulating layer located on the substrate and including a plurality of metal layers; a magnetic core; a first bottom winding and a second bottom winding of the transformer made of metal, the first bottom winding being in direct contact with a first metal layer of the plurality of metal layers, and the second bottom winding being in direct contact with a second metal layer of the plurality of metal layers; a first top winding and a second top winding of the transformer made of metal, located on the magnetic core, the first top winding being in direct contact with a first metal layer of the plurality of metal layers, and the second top winding being in direct contact with a second metal layer of the plurality of metal layers; an electronic component located on the insulating layer and connected to the transformer; and a molding material located on the electronic component. The first bottom winding and the first top winding are included in the primary winding of the transformer, and the second bottom winding and the second top winding are included in the secondary winding of the transformer, wherein the primary winding and the secondary winding of the transformer are not electrically connected to each other.

[0020] The substrate may include silicon. The transformer module may also include circuitry located on the substrate, and the transformer may be located on the same side of the substrate as the circuitry. The transformer may also include a PN junction in the substrate that isolates the primary and secondary sides of the transformer. The transformer module may also include input-output pads located on an opposite side of the substrate to the side of the substrate where the transformer is located.

[0021] Multiple top windings extend above the surface where electronic components are mounted. The metal can be copper.

[0022] According to a preferred embodiment of the present invention, a transformer module includes: a silicon substrate; circuitry located on a first side of the silicon substrate including input-output pads; an insulating layer located on a second side of the silicon substrate and including a magnetic core, a bottom metal winding of the transformer, and a top metal winding of the transformer, the bottom winding extending below the magnetic core and contacting the circuitry through the silicon substrate, the top winding extending around the magnetic core and contacting the circuitry through the silicon substrate; electronic components located on the insulating layer and connected to the transformer; and molding material located on the electronic components. The primary and secondary windings of the transformer are defined by portions of the bottom and top windings and are not electrically connected to each other.

[0023] The transformer may also include a PN junction in a silicon substrate that isolates the primary and secondary sides of the transformer. The metal may be copper.

[0024] The transformer module includes: a silicon substrate; circuitry located on a first side of the silicon substrate; an insulating layer located on a second side of the silicon substrate and including: a magnetic core; a metallic bottom winding of the transformer extending below the magnetic core and connected to the circuitry; and a metallic top winding of the transformer extending around the magnetic core and connected to the circuitry; a lead frame having input-output pads for connection to the transformer; and molding material covering the silicon substrate, the transformer, and the lead frame except for the input-output pads. The primary and secondary windings of the transformer are defined by portions of the bottom and top windings and are not electrically connected to each other.

[0025] The transformer may also include a PN junction in a silicon substrate that isolates the primary and secondary sides of the transformer. The transformer module may also include wires connecting the transformer to a lead frame. The metal may be copper.

[0026] The above and other features, components, characteristics, steps and advantages of the invention will become more apparent from the following detailed description of preferred embodiments of the invention with reference to the accompanying drawings. Attached Figure Description

[0027] Figure 1 This refers to an integrated transformer circuit module according to a preferred embodiment of the present invention.

[0028] Figures 2 to 25 Indicates manufacturing Figure 1 The transformer circuit module shown includes the following technological steps.

[0029] Figure 26 This refers to an integrated transformer circuit module according to another preferred embodiment of the present invention.

[0030] Figures 27 to 45 This indicates that the invention is manufactured using another preferred process. Figure 26The transformer circuit module shown includes the following technological steps.

[0031] Figure 46 This refers to an integrated transformer circuit module according to another preferred embodiment of the present invention.

[0032] Figure 47 This refers to an integrated transformer circuit module according to another preferred embodiment of the present invention.

[0033] Figure 48 This refers to the process of manufacturing photosensitive polyimide as an insulating layer. Detailed Implementation

[0034] Compared to traditional transformers, transformers integrated into a substrate allow for increased winding metal thickness. This enables the transformer to carry increased current while maintaining a smaller physical size. Consequently, such transformers can be integrated with other electronic components and used in smaller, higher-power circuits.

[0035] Figure 1 The figure shows a cross-section of an integrated transformer circuit module according to a preferred embodiment of the present invention. As shown, the circuit module may include: a silicon substrate 110; a transformer 100 within a redistribution layer (RDL), the redistribution layer (RDL) including a laminated metal layer 140 and an insulating layer 120 located on the silicon substrate 110; and circuitry overmolded on the RDL using a molding material 190.

[0036] Figure 1 The silicon substrate 110 may include doped regions defining source S and drain D, and a metal layer (e.g., within the dashed ellipse) defining the gate G of transistor 130. Transistor 130 may be interconnected via a metal layer 140 within insulating layer 120. Metal layer 140 may be formed using typical semiconductor processing techniques. Although silicon substrate 110 is silicon, other materials are also feasible, including ceramics, composite materials, laminated printed circuit boards (PCBs), or other suitable materials that may or may not include integrated circuits and wiring.

[0037] Figure 1The transformer 100 includes a metal winding wound around a magnetic core and connected to metal layers 140. The metal winding can be made of copper, aluminum, silver, gold, any other suitable metal, a combination of metal layers, or an alloy. For example, the winding can be made of copper-plated metal. The metal winding of the transformer can be thicker than the metal layers 140, which allows the metal winding of the transformer to carry higher currents. For example, the thickness of the metal winding can be about 15 μm or more within manufacturing tolerances, and the thickness of each metal layer 140 can reach about 3 μm within manufacturing tolerances. The magnetic core can be made of cobalt alloys such as CoNiFe, CoFeSi, CoZrO, CoZrTa, soft alloys such as Ni, Fe, NiFe, or any suitable magnetic material.

[0038] although Figure 1 This represents a single cross-section of transformer 100, but it should be understood that the transformer's metallic windings include a primary winding connected to the primary circuit and a secondary winding connected to the secondary circuit. An inductor can be used instead of transformer 100, which has only a single winding.

[0039] Figure 1 The PN junction 180 (within the dashed box) in the silicon substrate 110 is used for the circuit between the primary and secondary sides of the isolation transformer 100. For example, the power transistor on the primary side can be... Figure 1 The transistor on the right side is defined, and the synchronous rectifier on the secondary side can be... Figure 1 The transistor is defined on the left.

[0040] Larger electronic components 195, such as ceramic capacitors, diodes, MOSFETs, and on-chip circuits, can be located on the RDL. Electronic components 195 can be molded using a dielectric molding material 190, such as resin, to electrically isolate and environmentally protect them. Input-output I / O pads 160 for electrically interconnecting circuit modules to power supplies, control signals, external circuits, etc., can be located on the side of the silicon substrate 110 opposite to the RDL and can be connected to the RDL via silicon vias (TSVs) 175, although other interface features and techniques are also possible.

[0041] Figures 2 to 25 It indicates that it can be used for manufacturing Figure 1 The circuit module shown is illustrated with its sequential process steps. For simplicity, previous information about... Figure 1 The description of the features.

[0042] Figure 2This refers to the RDL, which includes a laminated insulating layer 220 and a metal layer 240, and the TSV 275 formed in and through the silicon substrate 210 using conventional semiconductor processing techniques. If the silicon substrate 210 is not silicon, the vias can be filled with a conductive material by plating, screen printing, or any other suitable process. Figure 3 This indicates the first seed metal 342 formed on the RDL. For example, the seed metal can be Ni, Cr, Au, Cu, or any other suitable material that can be deposited or electroplated on top of the RDL. Figure 4 This refers to a patterned resist film 480 that is configured to cover a portion of the first seed metal 442 and expose the other portions of the first seed metal 442.

[0043] Figure 5 This indicates that the bottom winding 552 of the transformer is formed by electrolytically plating copper onto the exposed portion of the first seed metal 542. Although Figure 5 This represents a single cross-section, but it should be understood that multiple electrically isolated bottom windings are formed. The bottom windings can be formed by a single step or multiple steps. In a transformer, some bottom windings define a portion of the primary winding, while others define a portion of the secondary winding. In an inductor, the bottom winding defines a portion of the inductor winding. Figure 6 In the steps shown, the resist film is stripped and the first seed metal is etched, leaving the bottom winding 652. The winding portion of the transformer or inductor defined by the bottom winding 652 and the remaining portion of the first seed metal are in direct contact with the top metal layer 640 and the top insulating layer 620. Figure 7 This indicates that an insulating layer 720 is formed on and around the bottom winding 752.

[0044] Figure 48 This refers to the process of manufacturing photosensitive polyimide (PSPI) as an insulating layer. Figure 48 The insulating layer 720 is formed by: (1) coating an uncured positive or negative PSPI 5 onto a substrate 10; (2) patterning the coated uncured PSPI 15 with ultraviolet (UV) radiation through a mask 90; (3) developing the irradiated coated uncured PSPI 25 to produce a patterned positive or negative image of the mask 90; and (4) curing the patterned PSPI 35 by heat treatment to expose a portion of the bottom winding 752. The insulating layer 720 may be polyimide, Su-8, phenolic resist, or any other suitable material.

[0045] Figure 8 This indicates that the second seed metal 844 is formed on the insulating layer 820 and contacts the previously exposed portion of the bottom winding 852. Figure 9This indicates that a patterned resist film 980 is formed on the second seed metal 944, thereby exposing a portion of the second seed metal 944. Figure 10 This indicates that the magnetic core 1060 is formed by electroplating any of the aforementioned materials onto the portion of the second seed metal exposed by the resist film 1080.

[0046] exist Figure 11 In the steps shown, the resist film is stripped off and the exposed second metal is etched away, thereby exposing the magnetic core 1160. Figure 12 This indicates that through previous discussions... Figure 48 The described process forms an insulating layer 1220 on and around the magnetic core 1260. Figure 13 This indicates that the third seed metal 1346 is formed on the insulating layer 1320 and contacts the exposed portion of the bottom winding 1352 in the contact hole CH.

[0047] Figure 14 The patterned resist film 1480 is formed on the third seed metal 1446, thereby exposing a portion of the third seed metal 1446 in the contact hole CH. Figure 15 This indicates that the winding connection portion 1555 of the transformer is formed by electrolytically plating copper onto the exposed portion of the third seed metal 1546. Figure 16 In the steps shown, the resist film is peeled off, thereby exposing the third metal 1646 and the winding connection 1655.

[0048] Figure 17 A patterned resist film 1780 is formed on the third seed metal 1746, thereby exposing the third seed metal 1746 and a portion of the winding connection 1755. Figure 18 This indicates that the top winding 1854 of the transformer is formed by electrolytic copper plating on the exposed portion of the third seed metal and the winding connection portion 1855, thereby forming an electrical connection with the bottom winding 1852. Although Figure 18 This represents a single cross-section, but it should be understood that the top winding 1854 is connected to different bottom windings. Multiple top windings can be formed in a single step or in multiple steps. In a transformer, some top windings define a portion of the primary winding, while others define a portion of the secondary winding. In an inductor, the top winding defines a portion of the inductor winding. Figure 19 This indicates that a patterned resist film 1980 is formed over portions of the top winding 1954 and the third seed metal 1946, thereby exposing portions of the top winding 1954.

[0049] Figure 20 This indicates that the RDL connection layer 2045 is formed by electrolytically plating copper on the exposed portion of the top winding 2054. Figure 21 This indicates that a patterned resist film 2180 is formed on the top winding 2154, thereby exposing the RDL connection layer 2145.

[0050] Figure 22 This indicates that RDL connection pads 2247 are formed by electrolytically plating copper onto the exposed portion of the RDL connection layer. Figure 23 In the steps shown, the resist film is stripped and the exposed third seed metal is etched to expose the top winding 2354, the RDL connection layer 2345 and the RDL connection pad 2347. Figure 24 This indicates that an insulating layer 2420 is formed on and around the top winding, RDL connection layer, and RDL connection pad 2447, thereby using the previously mentioned... Figure 48 The described process exposes RDL connection pads 2447. The entire top winding 2454 is covered by an insulating layer 2420, thereby improving the isolation of the circuit module.

[0051] Figure 25 This describes integrating circuitry and a transformer into a silicon substrate, where electronic components 2595 are connected to an RDL layer and then molded using a molding material 2590, such as phenolic resin, to complete an integrated transformer circuit module. Electronic components 2595 may include active components such as transistors, and passive components such as resistors, capacitors, inductors, and diodes. Electronic components 2595 can provide control signals. For example, if the integrated transformer circuit module is used in a DC-DC converter application, electronic components 2595 may include a control IC that, for example, regulates the power transistors on the primary side of the integrated transformer circuit module.

[0052] Figure 26 This is a cross-sectional view showing an integrated transformer circuit module according to another preferred embodiment of the present invention. Similar to... Figure 1 The preferred embodiment shown is Figure 26 The circuit module may include: a silicon substrate 2610; a transformer 2600 within an RDL, the RDL including a laminated metal layer 2640 and an insulating layer 2620 located on the silicon substrate 2610; and circuitry molded onto the RDL using a molding material 2690. However, as... Figure 26 As shown, the top winding 2654 in the transformer 2600 is formed to be in direct contact with the bottom winding 2652 without a winding connection layer. Furthermore, the top winding 2654 and the insulating material covering the top winding 2654 extend above the RDL.

[0053] The metal windings of the transformer, including the top winding 2654 and the bottom winding 2652, are thicker than the metal layer 2640, which allows the transformer's metal windings to carry higher currents. For example, within manufacturing tolerances, the thickness of the bottom winding 2652 can be about 15 μm and the thickness of the top winding 2654 can be about 15 μm or greater, and each metal layer 2640 can be up to about 3 μm within manufacturing tolerances. The transformer core can include any of the materials described above. Compared to conventional transformers, the top winding 2654 can be thicker than the bottom winding 2652, which allows the transformer to carry higher currents and has better heat dissipation capabilities.

[0054] although Figure 26 This represents a single cross-section of transformer 2600, but it should be understood that the transformer's metallic windings include a primary winding connected to the primary circuit and a secondary winding connected to the secondary circuit. An inductor can be used instead of transformer 2600, which has only a single winding.

[0055] Figures 27 to 45 It indicates that it can be used for manufacturing Figure 26 The circuit module shown is illustrated with its sequential process steps. For the sake of brevity, the descriptions of the previously described features can be omitted.

[0056] Figure 27 This refers to the RDL, which includes a laminated insulating layer 2720 and a metal layer 2740, and the TSV 2775 formed in and through the silicon substrate 2710 using conventional semiconductor processing techniques. Figure 28 This indicates the first seed metal 2842 formed on the RDL. Figure 29 This refers to a patterned resist film 2980 that is configured to cover a portion of the first seed metal 2942 and expose a portion of the first seed metal 2942.

[0057] Figure 30 This indicates that the bottom winding 3052 of the transformer is formed by electrolytic copper plating on the exposed portion of the first seed metal. Although Figure 30 This represents a single cross-section, but it should be understood that multiple electrically isolated bottom windings are formed. The bottom windings can be formed by a single step or multiple steps. In a transformer, some bottom windings define a portion of the primary winding, while others define a portion of the secondary winding. In an inductor, the bottom winding defines a portion of the inductor winding. Figure 31 In the steps shown, the resist film is stripped, and the first seed metal 3142 is etched, leaving the bottom winding 3152 and exposing a portion of the insulating layer 3120. The portion of the transformer or inductor winding defined by the bottom winding 3152 and the remaining portion of the first seed metal 3142 are in direct contact with the top metal layer 3140 and the top insulating layer 3120. Figure 32Indicates that through regarding Figure 48 The described process forms an insulating layer 3220 on and around the bottom winding 3252.

[0058] Figure 33 This indicates that the second seed metal 3344 is formed on the insulating layer 3320 and contacts the previously exposed portion of the bottom winding 3352. Figure 34 This indicates that a patterned resist film 3480 is formed on the second seed metal 3444, thereby exposing a portion of the second seed metal 3444. Figure 35 This indicates that the magnetic core 3560 is formed by electroplating any of the aforementioned materials onto the portion of the second seed metal exposed by the resist film 3580.

[0059] exist Figure 36 In the steps shown, the resist film is stripped off and the exposed second metal is etched away, thereby exposing the magnetic core 3660 and the insulating layer 3620. Figure 37 Indicates the use of information about Figure 48 The described process forms an insulating layer 3720 on and around the magnetic core 3760. Figure 38 This indicates that the third seed metal 3846 is formed on the insulating layer 3820 and is in contact with the exposed portion of the bottom winding 3852.

[0060] Figure 39 This indicates that a patterned resist film 3980 is formed on the third seed metal 3946, thereby exposing a portion of the third seed metal 3946. Figure 40 This indicates that the top winding 4054 of the transformer is formed by electrolytically plating copper onto the exposed portion of the third seed metal. Although Figure 40 This represents a single cross-section, but it should be understood that the top winding 4054 is connected to different bottom windings. Multiple top windings can be formed in a single step or multiple steps. In a transformer, some top windings define a portion of the primary winding, while others define a portion of the secondary winding. In an inductor, the top winding defines a portion of the inductor winding. Figure 18 In the steps shown, the resist film is stripped off, thereby exposing portions of the third seed metal 4146 and the top winding layer 4154.

[0061] Figure 42 This indicates that a patterned resist film 4280 is formed on a portion of the top winding and the third seed metal 4246, thereby exposing other portions of the third seed metal 4246, and RDL connection pads 4255 for discrete electronic components are formed by electrolytically plating copper onto the exposed portions of the third seed metal 4246. Figure 43 In the steps shown, the resist film is stripped off and the exposed third metal is etched away, thereby exposing the top winding 4354 and the RDL connection pad 4355. Figure 44 This indicates that an insulating layer 4420 is formed on and around the top winding and around the RDL connection pads 4455, thereby exposing the top surface of the RDL connection pads 4455 by patterning a resist film, heat-treating the resist film, and then peeling off the resist film. The entire top winding is covered by the insulating layer 4420, thereby improving the isolation of the circuit module.

[0062] Figure 45 This describes integrating circuitry and a transformer into a silicon substrate, where electronic component 4595 is connected to RDL connection pads and then molded using molding material 4590 (e.g., Su-8 or Novalac resin) to complete the integrated transformer circuit module. Electronic component 4595 may include active components such as transistors, and passive components such as resistors, capacitors, inductors, and diodes. Electronic component 4595 can provide control signals. For example, if the integrated transformer circuit module is used in a DC-DC converter application, electronic component 4595 may include a control IC that, for example, regulates the power transistors on the primary side of the integrated transformer circuit module.

[0063] Figure 46 This refers to an integrated transformer circuit module according to another preferred embodiment of the present invention. Figure 46 The silicon substrate 4610 may include doped regions defining source S and drain D, and a metal layer (e.g., within the dashed ellipse) defining the gate G of transistor 4630. Transistor 4630 may be interconnected via a metal layer 4640 within an insulating material 4620. The metal layer 4640 may be formed using typical semiconductor processing techniques.

[0064] Figure 46 The transformer 4600 includes copper-plated metal windings that are wound around a magnetic core and connected to metal layers 4640. The metal windings of the transformer are thicker than the metal layers 4640, which allows the metal windings to carry higher currents. For example, within manufacturing tolerances, the thickness of the bottom winding can be about 15 μm, the thickness of the top winding can be about 15 μm or greater, and the thickness of each metal layer 4640 can reach about 3 μm within manufacturing tolerances. The transformer core can be made of any of the materials described above.

[0065] although Figure 46 This represents a single cross-section of transformer 4600, but it should be understood that the transformer's metallic windings include a primary winding connected to the primary circuit and a secondary winding connected to the secondary circuit. An inductor can be used instead of transformer 4600, which has only a single winding.

[0066] Figure 46The diagram shows the PN junction 4680 (within the dashed box) in the silicon substrate 4610 used for the circuitry between the primary and secondary sides of the isolation transformer 4600. For example, the power transistor on the primary side could be... Figure 46 The transistor on the right side is defined, and the synchronous rectifier on the secondary side can be... Figure 46 The transistor is defined on the left.

[0067] Larger discrete electronic components 4695, such as ceramic capacitors, diodes, MOSFETs, on-chip circuits, etc., can be located on the RDL and connected to the plated connection pads of the RDL. For example... Figure 46 As shown, the transformer 4600 and silicon substrate 4610 can be mounted or connected to the lead frame 4665 using solder balls 4655 or other suitable methods. Optionally, discrete electronic components 4695 can be directly connected to the lead frame 4665 and / or directly connected to the bottom of the RDL.

[0068] Figure 46 The circuitry, including transformer 4600, silicon substrate 4610, electronic components 4695, and leadframe 4665, is encapsulated and molded using a dielectric molding material 4690 such as resin, thereby electrically isolating the circuitry and providing environmentally friendly physical protection. The input-output (I / O) pads 4660 of the leadframe 4665 can be used to electrically interconnect circuit modules to power supplies, control signals, external circuits, etc. For example, the I / O pads 4660 can be used to connect circuit modules to a main substrate or PCB (not shown).

[0069] Figure 46 The circuit module shown can be connected to... Figures 2 to 24 The method shown is similar to the one used in this process. Figure 24 Following the steps shown, leadframe 4665 can be connected to RDL, and electronic component 4695 can be connected to leadframe 4665 and / or RDL. The molded circuit module can then be covered with dielectric molding material 4690.

[0070] The transformer 4600 can extend below the bottom of the RDL, similar to... Figure 26 How does the 2600 transformer extend above the top surface of the RDL?

[0071] Figure 47 This refers to an integrated transformer circuit module according to another preferred embodiment of the present invention. Figure 47 The silicon substrate 4710 may include doped regions defining the source (S) and drain (D) and a metal layer (e.g., within the dashed ellipse) defining the gate (G) of the transistor 4730. The transistor 4730 can be interconnected via a metal layer 4740 within an insulating material 4720. The metal layer 4740 can be formed using typical semiconductor processing techniques.

[0072] Figure 47 The transformer 4700 includes copper-plated metal windings that extend around the core and are connected to metal layers 4740. The metal windings of the transformer are thicker than metal layers 4740, which allows the metal windings to carry higher currents. For example, within manufacturing tolerances, the thickness of the bottom winding can be about 15 μm, the thickness of the top winding can be about 15 μm or greater, and the thickness of each metal layer 4740 can reach about 3 μm within manufacturing tolerances. The core of the transformer can include any of the materials described above.

[0073] although Figure 47 This represents a single cross-section of transformer 4700, but it should be understood that the transformer's metallic windings include a primary winding connected to the primary circuit and a secondary winding connected to the secondary circuit. An inductor can be used instead of transformer 4700, which has only a single winding.

[0074] Figure 47 The diagram shows the PN junction 4780 (within the dashed box) in the silicon substrate 4710 used for the circuitry between the primary and secondary sides of the isolation transformer 4700. For example, the power transistor on the primary side could be... Figure 47 The transistor on the right side is defined, and the synchronous rectifier on the secondary side can be... Figure 47 The transistor is defined on the left.

[0075] Larger discrete electronic components 4795, such as ceramic capacitors, diodes, MOSFETs, and on-chip circuits, can be located on the RDL and connected to plated RDL connection pads. For example... Figure 47 As shown, transformer 4700 and silicon substrate 4710 can be mounted or connected to lead frame 4765. The RDL can be wire-coupled to lead frame 4765 using wire 4755 or other suitable methods. Alternatively, discrete electronic components 4795 can be connected to the RDL or directly to lead frame 4765.

[0076] Figure 47 The circuitry, including transformer 4700, silicon substrate 4710, electronic components 4795, leadframe 4765, and wires 4755, is encapsulated and molded using a dielectric molding material 4790 such as Su-8 or Novalac resin, thereby electrically isolating the circuitry and providing environmentally friendly physical protection. The input-output (I / O) pads 4760 of the leadframe 4765 are used to electrically interconnect the circuit module to power supplies, control signals, external circuitry, etc. For example, the I / O pads 4760 can be used to connect the circuit module to a main substrate or PCB (not shown).

[0077] Figure 47 The circuit module shown can be connected to... Figures 2 to 24 It is made using a method similar to that shown. Figure 24 Following the steps shown, lead frame 4765 can be connected to silicon substrate 4710, electronic component 4795 can be connected to lead frame 4765 and / or RDL, and wire bonding can be performed to form line 4755. The molded circuit module can then be covered with dielectric molding material 4790.

[0078] Figure 47 The transformer 4700 in the middle can extend above the top surface of the RDL, similar to... Figure 26 How does the 2600 transformer extend above the top surface of the RDL?

[0079] It should be understood that the above description is merely illustrative of the invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the scope of the invention. Therefore, the invention is intended to encompass all such alternatives, modifications, and variations falling within the scope of the appended claims.

Claims

1. A transformer module, comprising: a substrate; a plurality of metal layers and a plurality of insulating layers laminated on the substrate; first and second bottom windings of a transformer made of a metal, the first bottom winding in direct contact with a first metal layer of the plurality of metal layers and the second bottom winding in direct contact with a second metal layer of the plurality of metal layers; a first insulating layer of the plurality of insulating layers on the first and second bottom windings; a magnetic core on the first insulating layer; a second insulating layer of the plurality of insulating layers on the magnetic core; first and second top windings of the transformer made of the metal on the magnetic core and a portion of the second insulating layer, the first top winding in direct contact with the first metal layer of the plurality of metal layers and the second top winding in direct contact with the second metal layer of the plurality of metal layers; a third insulating layer of the plurality of insulating layers on the first and second top windings; an electronic component on the third insulating layer and connected with the transformer; and a molding material on the electronic component, wherein the first bottom winding and the first top winding are included in a primary winding of the transformer and the second bottom winding and the second top winding are included in a secondary winding of the transformer, and the primary winding and the secondary winding of the transformer are not electrically connected to each other. The substrate comprises silicon.

2. The transformer module of claim 1, wherein, 3. The transformer module of claim 1, further comprising a circuit on the substrate; wherein the transformer is on a same side of the substrate as the circuit.

4. The transformer module of claim 2, further comprising a PN junction in the substrate, the PN junction isolating a primary side and a secondary side of the transformer.

5. The transformer module of one of claims 1 to 4, further comprising an input- output pad on an opposite side of the substrate from a side on which the transformer is located. The first and second top windings extend above a surface on which the electronic component is mounted.

6. Transformer module according to one of claims 1 to 4, wherein The metal is copper.

7. Transformer module according to one of claims 1 to 4, wherein 8. A method of manufacturing a transformer module, comprising: providing a substrate; forming a plurality of metal layers on the substrate; depositing a metal to form first and second bottom windings of a transformer, the first bottom winding in direct contact with a first metal layer of the plurality of metal layers and the second bottom winding in direct contact with a second metal layer of the plurality of metal layers; forming a first insulating layer on the first and second bottom windings; electroplating a magnetic core on the first insulating layer; forming a second insulating layer on the magnetic core; ​ depositing the metal to form first and second top windings of the transformer on the second insulating layer, the first and second top windings extending around the magnetic core, the first top winding being in direct contact with the first metal layer of the plurality of metal layers, and the second top winding being in direct contact with the second metal layer of the plurality of metal layers; forming a third insulating layer on the first and second top windings; mounting an electronic component on the third insulating layer such that the electronic component is connected with the transformer; and overmolding the electronic component with a molding material, wherein the first bottom winding and the first top winding are included in a primary winding of the transformer, and the second bottom winding and the second top winding are included in a secondary winding of the transformer; and the primary winding and the secondary winding of the transformer are not electrically connected to each other.

9. The method of claim 8, wherein, the metal is electroplated copper.

10. A transformer module, comprising: a silicon substrate; circuitry on a first side of the silicon substrate including input-output pads; a bottom winding of metal of a transformer on a second side of the silicon substrate and in contact with the circuitry through the silicon substrate; a first insulating layer on the bottom winding; a magnetic core on the first insulating layer; a second insulating layer on the magnetic core; a top winding of the metal of the transformer extending around the magnetic core and a portion of the second insulating layer and in contact with the circuitry through the silicon substrate; a third insulating layer on the top winding; an electronic component on the third insulating layer and connected with the transformer; and a molding material on the electronic component, wherein a primary winding and a secondary winding of the transformer are defined by a portion of the bottom winding and the top winding and are not electrically connected to each other.

11. The transformer module of claim 10, further comprising a PN junction in the silicon substrate, the PN junction isolating a primary side and a secondary side of the transformer.

12. The transformer module of claim 10 or 11, wherein, the metal is copper.

13. A method of manufacturing a transformer module, the method comprising: providing a silicon substrate; forming circuitry on a first side of the silicon substrate including input-output pads; depositing a metal on a second side of the silicon substrate to form a bottom winding of a transformer in contact with the circuitry; forming a first insulating layer on the bottom winding; electroplating a magnetic core on the first insulating layer; forming a second insulating layer on the magnetic core; depositing the metal on the second insulating layer to form a top winding of the transformer extending around the magnetic core and in contact with the circuitry through the silicon substrate; forming a third insulating layer on the top winding; mounting an electronic component on the third insulating layer such that the electronic component is connected with the transformer; and overmolding the electronic component with a molding material, wherein a primary winding and a secondary winding of the transformer are defined by a portion of the bottom winding and the top winding and are not electrically connected to each other.

14. The method of claim 13, wherein, The metal is electroplated copper.

15. A transformer module, comprising: a silicon substrate; circuitry on a first side of the silicon substrate; a bottom winding of a metal of a transformer, the bottom winding on a second side of the silicon substrate and connected to the circuitry; a first insulating layer on the bottom winding; a magnetic core on the first insulating layer; a second insulating layer on the magnetic core; a top winding of the metal of the transformer, the top winding extending around the magnetic core and a portion of the second insulating layer and connected to the circuitry; a third insulating layer covering the top winding; a leadframe having input-output pads connected to the transformer; and a molding material covering the silicon substrate, the transformer, and the leadframe except for the input-output pads. The primary and secondary windings of the transformer are defined by the bottom winding and a portion of the top winding and are not electrically connected to each other.

16. The transformer module of claim 15, further comprising a PN junction in the silicon substrate, the PN junction isolating a primary side and a secondary side of the transformer.

17. The transformer module of claim 15 or 16, further comprising a wire connecting the transformer to the leadframe. The metal is electroplated copper.

18. The transformer module of claim 15 or 16, wherein, 19. A circuit module, comprising: a redistribution layer, comprising: a metal layer; an insulating layer; and a magnetic component comprising a first metal winding, the first metal winding extending around a magnetic core and connected to the metal layer; a substrate connected to a first side of the redistribution layer and comprising a first transistor and a second transistor; and an electronic component connected to a second side of the redistribution layer opposite the first side; wherein the first metal winding is thicker than the metal layer. The substrate comprises silicon and a PN junction between the first transistor and the second transistor.

20. The circuit module of claim 19, wherein, A portion of the first metal winding extends beyond a surface of the redistribution layer.

21. The circuit module of claim 19, wherein, The substrate comprises input-output pads on an opposite side of the substrate from the side of the substrate on which the redistribution layer is located.

22. The circuit module according to one of claims 19 to 21, wherein, 23. The circuit module of one of claims 19 to 21, further comprising a leadframe connected to the redistribution layer or the substrate.

24. The circuit module of claim 23, further comprising a wire; wherein the leadframe is connected to the substrate; and the wire is connected to the leadframe and the redistribution layer. The magnetic component is a transformer and further comprises a second metal winding extending around the magnetic core.

25. The circuit module according to one of claims 19 to 21, wherein, 26. The circuit module of claim 25, wherein the first transistor is connected to the first metal winding; and the second transistor is connected to the second metal winding. The first metal winding and the second metal winding are electrically isolated from each other.

27. The circuit module of claim 25, wherein, The magnetic component is an inductor.

28. The circuit module of one of claims 19 to 21, wherein, 29. A transformer module, comprising: a substrate; an insulating layer on the substrate and comprising: a plurality of metal layers; a magnetic core; and a redistribution layer on the substrate and comprising: a metal layer; an insulating layer; and a magnetic component comprising a first metal winding, the first metal winding extending around the magnetic core and connected to the metal layer. a first bottom winding and a second bottom winding of the transformer made of metal, the first bottom winding being in direct contact with a first metal layer of the plurality of metal layers and the second bottom winding being in direct contact with a second metal layer of the plurality of metal layers; and a first top winding and a second top winding of the transformer made of the metal, located on the magnetic core, the first top winding being in direct contact with the first metal layer of the plurality of metal layers, the second top winding being in direct contact with the second metal layer of the plurality of metal layers; an electronic component located on the insulating layer and connected with the transformer; and a molding material located on the electronic component, wherein the first bottom winding and the first top winding are included in a primary winding of the transformer and the second bottom winding and the second top winding are included in a secondary winding of the transformer, and the primary winding and the secondary winding of the transformer are not electrically connected to each other.

30. The transformer module of claim 29, wherein, the substrate comprises silicon.

31. The transformer module of claim 29, further comprising a circuit located on the substrate; wherein the transformer is located on the same side of the substrate as the circuit.

32. The transformer module of claim 30, further comprising a PN junction in the substrate, the PN junction isolating a primary side and a secondary side of the transformer.

33. The transformer module of one of claims 29 to 32, further comprising an input- output pad located on an opposite side of the substrate from the side of the substrate on which the transformer is located.

34. The transformer module according to one of claims 29 to 32, wherein, the plurality of top windings extend above a surface on which the electronic component is mounted.

35. The transformer module of one of claims 29 to 32, wherein, the metal is copper.

36. A transformer module, comprising: a silicon substrate; a circuit located on a first side of the silicon substrate that includes an input- output pad; an insulating layer located on a second side of the silicon substrate and comprising: a magnetic core; a bottom winding of the transformer of metal, the bottom winding extending below the magnetic core and in contact with the circuit through the silicon substrate; and a top winding of the transformer of the metal, the top winding extending around the magnetic core and in contact with the circuit through the silicon substrate; an electronic component located on the insulating layer and connected with the transformer; and a molding material located on the electronic component, wherein a primary winding and a secondary winding of the transformer are defined by a portion of the bottom winding and the top winding and are not electrically connected to each other.

37. The transformer module of claim 36, further comprising a PN junction in the silicon substrate, the PN junction isolating a primary side and a secondary side of the transformer.

38. The transformer module of claim 36 or 37, wherein, the metal is copper.

39. A transformer module, comprising: a silicon substrate; a circuit located on a first side of the silicon substrate; an insulating layer located on a second side of the silicon substrate and comprising: a magnetic core; a bottom winding of the transformer of metal, the bottom winding extending below the magnetic core and in contact with the circuit; and a top winding of the transformer of the metal, the top winding extending around the magnetic core and in contact with the circuit. a top winding of the metal of the transformer, the top winding extending around the magnetic core and connected with the circuit; a lead frame having input-output pads connected with the transformer; and a molding material covering the silicon substrate, the transformer, and the lead frame except the input-output pads, wherein the primary winding and the secondary winding of the transformer are defined by the bottom winding and a portion of the top winding and are not electrically connected to each other.

40. The transformer module of claim 39, further comprising a PN junction in the silicon substrate, the PN junction isolating a primary side and a secondary side of the transformer.

41. The transformer module of claim 39 or 40, further comprising wires connecting the transformer to the lead frame.

42. The transformer module of claim 39 or 40, wherein, the metal is copper.

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