Semiconductor Package TSV Structure for Low-Damage Via Drilling
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Solution Overview
Problem
The miniaturization of electronic devices has highlighted the need for improved heat dissipation and more reliable through via connections in semiconductor devices, as existing methods for forming via holes in semiconductor packaging can lead to thermal damage and reduced strength of the substrate, affecting data transmission speed and reliability.
Innovation Solution
The use of diode-pumped solid state (DPSS) lasers with lower power and higher repetition rates for via-hole drilling in ceramic substrates, which results in less thermal damage and facilitates the formation of tapered via holes that enhance seed material deposition and plating processes, improving the reliability and electrical performance of semiconductor packages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If higher-powered laser systems are used for via-hole drilling, then drilling speed and productivity are improved, but thermal damage and cracking of the substrate increase
Solution Approach 1:
The patent employs pulsed laser drilling instead of continuous wave laser drilling. The laser operates in periodic pulses with controlled duration and repetition rate, allowing the material to cool between pulses. This periodic action enables faster drilling speeds while limiting cumulative thermal energy input, thereby reducing thermal damage and cracking in the ceramic substrate.
Solution Approach 2:
The patent changes the laser operating parameters from high power continuous mode to lower power pulsed mode with optimized repetition rate and pulse width. By adjusting these parameters, the drilling productivity is maintained or improved while the peak power density is controlled to minimize thermal diffusion and damage to the substrate.
2Reliability
If via holes are formed in ceramic substrates, then electrical connections are established, but the substrate strength is reduced
Solution Approach 1:
Pulsed laser drilling creates via holes with minimal thermal affect zones, preserving the mechanical integrity of the ceramic substrate. The periodic pulsing allows stress relaxation between pulses, preventing crack propagation and maintaining substrate strength while still forming reliable electrical connections through the via holes.
Solution Approach 2:
The patent replaces mechanical drilling methods with laser-based ablation. This substitution eliminates mechanical contact forces that could cause substrate cracking, while the laser energy is precisely controlled to remove material cleanly and form via holes that maintain substrate structural strength.
3Reliability
If thermal damage is reduced during via-hole drilling, then substrate reliability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The pulsed laser regime with optimized pulse width and repetition rate provides precise control over material removal. Each pulse removes a controlled amount of material with minimal heat diffusion, enabling accurate via hole formation with clean edges and consistent dimensions, thereby meeting manufacturing precision requirements while reducing thermal damage.
Solution Approach 2:
The patent incorporates real-time monitoring and feedback control of the laser drilling process. By monitoring drilling depth, via hole formation progress, and thermal conditions, the system dynamically adjusts laser parameters to maintain precise via hole dimensions while minimizing thermal damage to the substrate.
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 the thermal conductivity of semiconductor packages, improves the reliability of through substrate vias, and increases the electrical performance by reducing thermal damage and cracking, while also reducing costs associated with higher-powered laser systems.
Implementation Method 1
The use of diode-pumped solid state (DPSS) lasers with lower power and higher repetition rates for via-hole drilling in ceramic substrates
Data Source
AI summary
A semiconductor package and a manufacturing method are provided. The semiconductor package includes a carrier substrate, a through substrate via (TSV), a first conductive pattern, and an encapsulated die. The TSV penetrates through the carrier substrate and includes a first portion and a second portion connected to the first portion, the first portion includes a first slanted sidewall with a first slope, the second portion includes a second slanted sidewall with a second slope, and the first slope is substantially milder than the second slope. The first conductive pattern is disposed on the carrier substrate and connected to the first portion of the TSV. The encapsulated die is disposed on the carrier substrate and electrically coupled to the TSV through the first conductive pattern.