Semiconductor Package Internal Routing via Laser Ablation
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Solution Overview
Problem
The increasing semiconductor circuit density poses interconnect challenges for the thermal, mechanical, and electrical integrity of packaged chips, necessitating improved routing capabilities in semiconductor packages.
Innovation Solution
A semiconductor package is manufactured with an internal routing circuit formed from multiple molding routing layers, where un-designed conductive areas are blasted away using a laser to create conductive paths on each molding compound layer, and additional metal routing layers are formed with unnatural surface roughness to enhance adhesion and routing capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If semiconductor circuit density is increased, then circuit performance is improved, but interconnect challenges worsen affecting thermal, mechanical and electrical integrity
Solution Approach 1:
The patent transitions from planar routing to three-dimensional routing by stacking multiple molding compound layers with conductive paths on each layer. This vertical dimensionality allows circuits to route in multiple directions and planes, reducing congestion and improving thermal/mechanical/electrical integrity while maintaining high circuit density.
Solution Approach 2:
The patent divides the routing function into multiple discrete molding compound layers, each containing specific conductive paths. This segmentation allows independent optimization of each layer's routing pattern and provides better thermal management by distributing heat across multiple layers rather than concentrating it in a single plane.
2Adaptability or versatility
If multiple molding routing layers are added, then routing capabilities are improved, but device complexity increases
Solution Approach 1:
The molding compound serves multiple functions simultaneously: it provides mechanical support, electrical insulation, thermal management, and hosts conductive routing paths. This multi-functionality reduces the need for separate structural components, thereby managing complexity while enabling three-dimensional routing capabilities.
Solution Approach 2:
The patent merges the routing function with the existing molding compound structure rather than adding separate routing layers. By integrating conductive paths directly into the molding compound layers, the design combines structural and routing functions, reducing overall package complexity compared to traditional multi-layer PCB approaches.
3Manufacturing precision
If laser blasting is used to create conductive paths, then manufacturing precision is improved, but manufacturing complexity increases
Solution Approach 1:
The patent replaces traditional mechanical drilling or punching methods with laser blasting to create conductive paths through molding compound layers. This substitution enables higher precision and more flexible path geometries while the automated laser process actually reduces operational complexity compared to manual or mechanical methods.
Solution Approach 2:
The laser blasting process allows dynamic adjustment of parameters such as pulse duration, power, and scanning speed to optimize conductive path creation for different materials and geometries. This parameter flexibility enables high precision manufacturing while maintaining ease of manufacture through programmable control rather than complex mechanical setups.
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 semiconductor package's routing capabilities, ensuring improved thermal, mechanical, and electrical integrity by creating a robust internal routing circuit that effectively connects die terminals to package terminals through multiple conductive layers.
Implementation Method 1
using a laser to blast away un-designed conductive areas to create conductive paths on each molding compound layer
Implementation Method 2
an intermediary insulation layer formed on top of the previous routing layer. The plurality of interconnections protrudes from a top surface of the intermediary insulation layer that has an unnatural surface roughness that is rougher than the natural surface roughness
Data Source
AI summary
Embodiments of the present invention are directed to a method of manufacturing a semiconductor package with an internal routing circuit. The internal routing circuit is formed from multiple molding routing layers in a leadframe land grid array semiconductor package by using a laser to blast away un-designed conductive areas to create conductive paths on each molding compound layer of the semiconductor package.