Silicon Transformer Chip With Thick Copper Windings for High Current
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Solution Overview
Problem
Conventional power supplies and DC-DC converters require larger discrete magnetic components that generate heat, emit electromagnetic interference, and are costly, making them unsuitable for small, efficient, and cost-effective applications like battery-operated devices.
Innovation Solution
A transformer is integrated into a silicon substrate using plated metal layers and insulating materials, with a core and windings that are electroplated with copper, allowing for increased current transmission while maintaining a small physical size, and electrical isolation between primary and secondary circuitry through a PN junction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If discrete magnetic components are used, then power transmission capability is sufficient, but device size becomes large and heat generation increases
Solution Approach 1:
The patent combines the transformer with the silicon substrate, integrating magnetic components directly onto the substrate rather than using discrete components. This merging reduces overall device size while maintaining power transmission capability through direct coupling of the transformer windings to the substrate circuitry.
Solution Approach 2:
The transformer is fabricated using multiple laminated metal layers stacked in three-dimensional space on the silicon substrate. This dimensional approach allows high power transmission through thick copper windings while keeping the footprint small, effectively moving from a planar to a volumetric design.
2Power
If discrete magnetic components are used, then power transmission capability is sufficient, but heat generation and electromagnetic interference increase
Solution Approach 1:
By integrating the transformer directly onto the silicon substrate, the patent reduces the distance between magnetic components and heat sinks, improving thermal management. The close integration also reduces electromagnetic interference by minimizing loop areas and coupling distances.
Solution Approach 2:
The silicon substrate acts as an intermediary that provides both electrical isolation and thermal conduction pathways. The substrate mediates between the transformer windings and the external environment, managing heat dissipation and electromagnetic field containment.
3Volume of moving object
If planar inductors are fabricated on silicon substrates, then device size is reduced, but current handling capability becomes insufficient for high-current operation
Solution Approach 1:
The patent uses multiple laminated metal layers stacked vertically to create thick copper windings for the transformer. This three-dimensional construction provides low resistance paths for high current while maintaining a small planar footprint, directly addressing the limitation of planar inductors.
Solution Approach 2:
The transformer employs laminated copper layers with insulating barriers between them, creating a composite structure that provides both high current carrying capacity through the copper and electrical isolation through the insulating layers. This composite approach enables high-current operation in a compact form.
4Ease of manufacture
If conventional silicon processes with insulation material are used, then manufacturing is simple, but electrical isolation between primary and secondary circuitry requires larger distances
Solution Approach 1:
The patent uses a PN junction formed in the silicon substrate as an active electrical isolation barrier between primary and secondary circuitry. This junction acts as a mediator that provides effective isolation with minimal spacing, replacing the need for large insulation material barriers.
Solution Approach 2:
The patent changes the isolation mechanism from passive insulation material thickness to active PN junction properties. By utilizing the electrical characteristics of the PN junction (depletion region, blocking behavior), effective isolation is achieved with much smaller physical dimensions than would be required by insulation material alone.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The transformer can handle higher currents in smaller volumes, enabling its use in smaller-volume, higher-power applications without the drawbacks of conventional components, such as heat generation and electromagnetic interference.
Implementation Method 1
a transformer includes a silicon substrate, a plurality of metal layers and a plurality of insulating layers laminated on the silicon substrate, a first bottom winding of a metal contacting a first metal layer of the plurality of metal layers and a second bottom winding of copper contacting a second metal layer of the plurality of metal layers
Implementation Method 2
transformers are fabricated using plated metal layers on a silicon substrate. Transformers including a core are made by a plating process
Implementation Method 3
circuitry on the primary side and circuitry on the secondary side of the transformer can coexist on the silicon substrate and can be electrically isolated from each other by a PN junction
Data Source
AI summary
A transformer includes a silicon substrate, a plurality of metal layers and a plurality of insulating layers laminated on the silicon substrate, a bottom winding of a metal contacting a first metal layer and a second metal layer of the plurality of metal layers, a first insulating layer on the bottom winding, a core on the first insulating layer, a second insulating layer on the core, a top winding of the metal that extends around the core and a portion of the second insulating layer, and a third insulating layer on the top winding. At least one of the top winding and the bottom winding is thicker than each of the plurality of metal layers.