Laser-Cut Lead Frames for Precise IC Package Miniaturization
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Solution Overview
Problem
Existing methods for fabricating integrated circuit (IC) packages, such as etching lead-frame sheets, are inefficient, costly, and limit miniaturization due to imprecise shaping and high production costs.
Innovation Solution
The use of laser-cutting to form lead-frame sheets from conductive metal material sheets, which includes features like through-holes and three-dimensional locking features, allowing for more precise and efficient fabrication of IC packages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional etching process is used to form lead-frame sheets, then chemical deposition can dissolve portions of conductive metal to form divisions and separations, but the process is inefficient, costly, and limits miniaturization due to imprecise shaping
Solution Approach 1:
The patent replaces the traditional chemical etching process with a laser-based cutting process. The laser cutting system uses a focused laser beam to precisely cut the lead-frame sheet, eliminating the need for chemical deposition and dissolution steps. This substitution of mechanical/thermal energy for chemical processes achieves superior shaping precision while significantly improving fabrication efficiency and enabling miniaturization of IC packages
Solution Approach 2:
The patent changes the fundamental processing parameters from chemical concentration and deposition time to laser power, cutting speed, and focal position. By controlling laser parameters such as power density, pulse duration, and scanning speed, the process achieves precise control over the lead-frame sheet geometry, enabling features that were impossible with traditional etching while maintaining high production rates
2Manufacturing precision
If traditional etching process is used, then chemical deposition forms divisions and separations, but high production costs are incurred
Solution Approach 1:
The patent replaces expensive chemical etching processes with a laser cutting system that uses focused optical energy. This eliminates the need for costly chemical deposits, dissolution chemicals, and extensive post-processing steps. The laser process directly forms through-holes, locking features, and other geometric features in a single step, significantly reducing material and processing costs while achieving superior precision
Solution Approach 2:
The patent extracts and eliminates the chemical deposition and dissolution steps from the manufacturing process. By using laser cutting, the process directly removes material to form the required features without requiring chemical deposits or subsequent dissolution steps, thereby eliminating the associated costs and complexity of chemical handling, waste disposal, and process control
3Manufacturing precision
If laser-cutting is used to form lead-frame sheet, then precise features like through-holes and three-dimensional locking features can be formed, but additional processing steps are required
Solution Approach 1:
The patent merges multiple traditional fabrication steps into a single laser cutting operation. The laser process simultaneously forms through-holes, locking features, separations, and other geometric features in one continuous process, eliminating the need for multiple sequential steps such as chemical deposition, etching, and mechanical punching. This consolidation reduces process complexity despite the advanced capabilities enabled
4Productivity
If traditional mechanical separation is used to singulate IC packages, then IC packages can be separated from the block, but the process is less clean and requires tie-bars and cross-bars
Solution Approach 1:
The patent replaces traditional mechanical sawing or breaking processes with laser cutting for singulation. The laser beam precisely cuts through the lead-frame sheet and packaging material to separate individual IC packages from the block without requiring tie-bars, cross-bars, or other structural reinforcements. This eliminates mechanical complexity while achieving clean, precise separations that maintain package integrity
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
Laser-cutting leads to a more efficient and cost-effective fabrication process, enabling better miniaturization of IC packages, reduced need for tie-bars and cross-bars, and cleaner singulation of IC packages.
Implementation Method 1
laser-cutting the conductive metal material sheet to form a lead-frame sheet
Implementation Method 2
laser-cutting the conductive metal material sheet to form at least one of through-holes and three-dimensional locking features
Data Source
AI summary
One example described herein includes a method for fabricating integrated circuit (IC) packages. The method includes fabricating a plurality of IC dies and providing a conductive metal material sheet. The method also includes laser-cutting the conductive metal material sheet to form a lead-frame sheet. The lead-frame sheet includes at least one of through-holes and three-dimensional locking features. The method further includes coupling the IC dies to the lead-frame sheet and coupling the lead-frame sheet and the IC dies to packaging material to form an IC package block comprising the IC packages.