PIC Package Adiabatic Well for Modulator Thermal Isolation

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Solution Overview

Problem

Heat management in silicon photonics devices is challenging due to the presence of sensitive optical components like wavelength modulators, which require precise temperature control, and traditional heat dissipation methods are ineffective, leading to performance issues and reduced lifespan.

Innovation Solution

A semiconductor package design incorporating a photonic integrated circuit (PIC) die with a heating element thermally coupled to the modulator, featuring an adiabatic well and thermal isolation structures such as a Thermal Isolation Bump (TIB) and intra-die seal ring to isolate heat-sensitive components, enhancing thermal management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If traditional heat dissipation methods are used, then heat can be dissipated from the device, but the wavelength modulator cannot be precisely temperature controlled and overheating occurs

Engineering Contradiction:

Improvetemperature control precision of wavelength modulatorVSAvoiddevice reliability due to overheating

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The device is segmented into distinct thermal zones: a heated region containing the wavelength modulator and heater, and a cold region containing other components. The adiabatic well physically separates these zones, allowing independent temperature control of the modulator while preventing heat from affecting other components.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The adiabatic well acts as a thermal intermediary or barrier between the heater and the substrate. This intermediate structure prevents direct thermal coupling, allowing the heater to warm the modulator precisely without transferring excessive heat to the substrate and causing overheating issues.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Temperature

If heating element is added for temperature control, then wavelength modulator temperature can be controlled, but heat affects surrounding components causing degradation

Engineering Contradiction:

Improvetemperature control of wavelength modulatorVSAvoidheat damage to polyimide and underfill materials

Core Design Contradiction:

TemperatureVSObject-affected harmful factors

Solution Approach 1:

The harmful heat effect is extracted and contained within the adiabatic well structure. By removing the direct thermal path from the heater to the substrate through the adiabatic barrier, the heat is effectively isolated to the modulator region, preventing it from reaching and degrading the polyimide and underfill materials.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The heat that would normally be harmful to surrounding materials is converted into a beneficial localized heating source for the wavelength modulator. The adiabatic well directs the heater's thermal energy precisely where needed while preventing it from becoming harmful to other components.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Temperature

If thermal isolation structures are added, then heat insulation is improved, but device complexity increases

Engineering Contradiction:

Improveheat insulation performanceVSAvoidpackage structure complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

Thermal isolation is applied locally only where needed - specifically around the wavelength modulator and heater region - rather than throughout the entire device. The adiabatic well is positioned strategically to provide heat insulation precisely at the critical interface between the heated modulator and the substrate, maintaining simplicity in non-critical areas.

Inventive Principle:

Principle #3Local quality

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 design provides superior heat insulation, preventing overheating of polyimide and underfill materials, reducing degradation, and allows independent control of the heater, improving the reliability and longevity of silicon photonics packages without compromising performance.

Implementation Method 1

an adiabatic well configured to provide thermal isolation between the heating element, the wavelength modulator, and the substrate

Methodology Applied

Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

a heating element thermally coupled to the wavelength modulator

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS20260005207A1Semiconductor package with adiabatic well structure

Publication Date: 2026.01.01 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

In an embodiment, a semiconductor package may include a photonic integrated circuit (PIC) die having a wavelength modulator and a heating element thermally coupled to the wavelength modulator. The semiconductor package may also include an interconnect structure on the PIC die, where the interconnect structure may include a plurality of conductive features and a void. The void overlaps with the heating element and the wavelength modulator from a top view. The package may furthermore include a plurality of conductive connectors over the interconnect structure and electrically connected to the plurality of conductive features.