Embedded SiP Transformer Layout Without Die Overlap
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Solution Overview
Problem
Current semiconductor devices with embedded transformers face issues such as high costs, electrical performance losses due to metal coupling, and unsuitability for power applications due to size constraints and complex assembly processes.
Innovation Solution
The integration of coils in a System in a Package (SiP) using Panel Embedded Package (PEP) technology, which forms coils in metallization levels without overlapping with the die, utilizing LDS/DCI technology to replace wire bonding and reduce package thickness and footprint, and improve electrical performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a transformer is formed starting from a core laminate, then the transformer can be integrated in a package, but the manufacturing cost increases and coupling losses occur due to metal frame shielding
Solution Approach 1:
The patent extracts and removes the metal frame/leadframe portions that cause coupling losses and shielding effects. By eliminating these metallic structures that interfere with transformer performance, the invention achieves better electrical performance without the harmful metal shielding while maintaining transformer integration in the package.
Solution Approach 2:
The patent merges the transformer structure directly with the package substrate using PEP technology, integrating the coils into the package molding itself rather than using separate core laminate assemblies. This consolidation eliminates the need for distinct metal frames and leadframe portions, reducing both cost and coupling losses while achieving reliable transformer integration.
2Ease of operation
If leadframe portions are used to support the transformer, then the transformer can be mounted in the package, but coupling losses occur due to metal shielding effects
Solution Approach 1:
The patent removes the leadframe portions entirely, replacing them with a non-conductive package substrate that supports the transformer coils. This extraction of metallic support structures eliminates the shielding effects and coupling losses while maintaining the ability to mount and support the transformer in the package.
Solution Approach 2:
The patent introduces a non-conductive package substrate as an intermediary material to support the transformer coils instead of using metallic leadframe portions. This mediator provides mechanical support without causing electromagnetic shielding or coupling losses, enabling easy transformer mounting while preserving electrical performance.
3Area of stationary object
If a transformer with die-sized dimensions is integrated using FOPLP technology, then the package size is reduced, but the transformer becomes unsuitable for power applications
Solution Approach 1:
The patent utilizes the third dimension (vertical stacking) by forming coils in multiple metallization levels of the package substrate. This allows the transformer to achieve larger effective area and power handling capability without increasing the package footprint, making it suitable for power applications while maintaining compact dimensions.
Solution Approach 2:
The patent nests multiple coil structures within the package substrate using PEP technology, where coils are formed in different metallization levels that are stacked vertically. This nested arrangement allows the transformer to provide sufficient power handling capability for power applications while maintaining a compact die-sized footprint.
4Reliability
If wire bonding is used to connect the transformer, then electrical connections can be established, but resistance increases and assembly complexity increases
Solution Approach 1:
The patent merges the electrical connection function into the package substrate itself by forming coils and interconnections directly in the substrate metallization levels. This integration eliminates the need for separate wire bonding operations, reducing assembly complexity while maintaining reliable electrical connections with lower resistance.
Solution Approach 2:
The patent extracts and removes the wire bonding process entirely, replacing it with direct metallization interconnections formed in the package substrate. This elimination of the wire bonding step simplifies the assembly process while achieving reliable electrical connections with reduced resistance through direct copper interconnections.
5Reliability
If metal pads are used for the coil connections, then electrical connections can be made, but inductance decreases and electrical performance deteriorates
Solution Approach 1:
The patent extracts and removes the metal pad structures from the coil connection design, replacing them with direct metallization interconnections formed in the package substrate. This elimination of metal pads preserves the magnetic field distribution and maintains high inductance values while still achieving reliable electrical connections through the substrate metallization.
Solution Approach 2:
The patent introduces the package substrate metallization as an intermediary structure that provides electrical connections without using traditional metal pads. This mediator maintains the magnetic field integrity and preserves inductance while enabling reliable electrical connections through the integrated substrate interconnection system.
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
This approach enhances inductance, reduces resistance, increases coupling coefficient and Q-factor, and offers cost reduction while simplifying assembly and improving electrical performance by eliminating metal pads and wire bonding, making the package more suitable for power applications.
Implementation Method 1
coils can be formed in metallization levels of PEP technology giving rise to a System in Package layout wherein the die/dice and the coil/coils are (at least substantially) not overlapping with each other
Data Source
AI summary
Semiconductor devices of the type currently referred to as a System in a Package (SiP) and having embedded therein a transformer are produced by embedding at least one semiconductor chip in an insulating encapsulation at a first portion thereof. Over a second portion thereof at least partly non-overlapping with the first portion, a stacked structure is formed including multiple layers of electrically insulating material as well as respective patterns of electrically conductive material. The respective patterns of electrically conductive material have: a planar coil geometry for providing electrically conductive coils such as the windings of a transformer and a geometrical distribution providing electrically conductive connections to one or more semiconductor chips.