Mixed Signal Package With Diamond Heat Spreader and Integrated Decoupling
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Solution Overview
Problem
Conventional microelectronic packages fail to simultaneously address low junction temperatures, low parasitics in interconnects, and short path lengths between the die and passive components for high-speed, high-power mixed signal circuits, leading to unacceptable signal noise and performance issues.
Innovation Solution
A microelectronic assembly that integrates decoupling capacitors within the device package, utilizing a high thermal conductivity diamond heat spreader and a ball grid array package with a stiffening member to reduce parasitic inductance and enhance thermal management, while maintaining short interconnect paths and low parasitics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If decoupling capacitors are placed on the PCB outside the device package, then the number of passive components on the PCB increases, but the parasitic inductance in the interconnections between the capacitors and the IC increases, leading to signal noise and performance degradation
Solution Approach 1:
The patent integrates decoupling capacitors inside the device package with the IC, merging the IC and passive components into a single packaged unit. This eliminates the need for separate PCB mounting of capacitors and reduces the parasitic inductance of interconnections by placing the capacitors in close proximity to the IC within the same package, thereby reducing signal noise and improving reliability.
Solution Approach 2:
The device package is designed to nest multiple components including the IC and decoupling capacitors within a single housing. The capacitors are positioned inside the package cavity in close proximity to the IC, creating a nested arrangement that minimizes interconnection path lengths and parasitic inductance while reducing the overall number of external components.
2Temperature
If conventional device packages are used for high-power mixed signal ICs, then the IC is mechanically protected, but the junction temperature becomes unacceptably high due to insufficient thermal management
Solution Approach 1:
The patent introduces a thermally conductive intermediary material (such as diamond or diamond-like carbon) between the IC and the package lid or heat sink. This intermediary material has high thermal conductivity that exceeds conventional thermal interface materials, enabling efficient heat transfer from the IC to the external environment while maintaining mechanical protection, thereby reducing junction temperature in high-power applications.
3Reliability
If the distance between the IC and decoupling capacitors is increased to reduce parasitic inductance, then the signal noise decreases, but the path length for electrical interconnections increases, adding more parasitic inductance
Solution Approach 1:
By merging the IC and decoupling capacitors into a single packaged unit with the capacitors positioned immediately adjacent to the IC, the patent achieves the shortest possible interconnection path length. This eliminates the need for long PCB traces and external connections, thereby minimizing parasitic inductance while maintaining low signal noise through optimal placement of the capacitors in close proximity to the IC power and ground pins.
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 solution effectively reduces parasitic inductance and thermal management challenges, enabling low noise and high dynamic range operation for high-speed, high-power mixed signal circuits by housing decoupling capacitors within the package and using a high thermal conductivity heat spreader.
Implementation Method 1
a diamond heat spreader in contact with the semiconductor die to improve the flow of heat
Data Source
AI summary
An improved microelectronic assembly (100) and packaging method includes a device package for housing a semiconductor die or chip, (105), an array of passive electronic components (305-355) operating in cooperation with the flip chip semiconductor die (105) and housed inside the device package to decouple noise from input signals, and a heat spreader (195) disposed between a top surface of the semiconductor die (105) and a package cover (185). The semiconductor die (105) is configured as a flip chip die and the device package includes a package substrate (110) configured as a ball grid array. The improved microelectronic device (100) reduces parasitic inductance in electrical interconnections between the semiconductor die and an electrical system substrate (115) and reduces signal noise in mixed signal high frequency analog to digital converters operating at clock rates above 1 GHz.