Leadframe Package Layout for Vertical Passive Component Integration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current techniques for integrating passive components in semiconductor packages face challenges such as poor electrical performance due to long connection formations and the complexity of multi-layer fabrication processes, especially in smaller Quad-Flat No-Lead (QFN) devices, which require more expensive and intricate processes to save PCB space.
Innovation Solution
A method involving a leadframe package with a two-terminal Surface Mount Device (SMD) mounted vertically on a die-pad, coupled to a leadframe, using laser direct structuring (LDS) activatable molding material to form conductive patterns and connections between semiconductor chips and passive components, reducing impedance and simplifying the fabrication process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If passive components are integrated into IC device packages to save PCB space, then PCB miniaturization is facilitated, but electrical performance deteriorates due to long connection formations
Solution Approach 1:
The patent transitions from planar (2D) component layout to three-dimensional (3D) vertical stacking. Passive components are positioned above the semiconductor die in the Z-direction, with conductive vias providing vertical electrical connections. This dimensional change reduces the horizontal footprint on the PCB while minimizing connection path lengths, thereby improving electrical performance without sacrificing space efficiency.
Solution Approach 2:
The patent implements nesting by placing passive components within the package structure that contains the semiconductor die. The passive components are embedded in the package substrate or mounted on intermediate layers, effectively nesting multiple functional elements within a compact hierarchical structure. This allows both active and passive components to coexist in a small volume while maintaining short interconnection paths.
2Quantity of substance
If multiple layers are used in QFN devices to integrate more components, then component integration increases, but fabrication complexity and cost increase
Solution Approach 1:
The patent combines multiple functions into a single-layer package substrate. Instead of using separate layers for different components and interconnections, the design integrates passive components, conductive vias, and interconnect traces on the same substrate layer. This merging approach reduces the number of fabrication steps required for multi-layer construction while achieving high component integration density.
Solution Approach 2:
The package substrate serves multiple functions simultaneously: it provides mechanical support for the semiconductor die and passive components, establishes electrical connections through integrated vias and traces, and enables signal routing without requiring separate dedicated layers. This multi-functionality reduces fabrication complexity while maintaining the ability to integrate numerous components.
3Area of stationary object
If component integration in smaller QFN devices is increased, then PCB space is reduced, but fabrication processes become more expensive and intricate
Solution Approach 1:
The patent achieves high component integration in small QFN packages by utilizing vertical stacking in the Z-dimension. Passive components are positioned above the die with short vertical vias for electrical connection, eliminating the need for extensive horizontal routing on multiple layers. This dimensional approach maximizes component density within the limited PCB footprint while maintaining simple single-layer or reduced-layer fabrication processes.
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 achieves up to 40% impedance reduction in capacitive components above 30 MHz and facilitates the integration of passive components in single-layer packages, reducing fabrication complexity and costs while maintaining improved electrical performance.
Implementation Method 1
forming a laser direct structuring (LDS) activatable molding material over the semiconductor chip, passive component, and the at least one leadframe portion. The method further includes forming desired patterns of structured areas within the LDS activatable molding material
Data Source
AI summary
Disclosed herein is a method, including attaching a semiconductor chip to a chip mounting portion on at least one leadframe portion, and attaching a passive component on a passive component mounting portion of the at least one leadframe portion. The method further includes forming a laser direct structuring (LDS) activatable molding material over the semiconductor chip, passive component, and the at least one leadframe portion. Desired patterns of structured areas are formed within the LDS activatable molding material by activating the LDS activatable molding material. The desired patterns of structured areas are metallized to form conductive areas within the LDS activatable molding material to thereby form electrical connection between the semiconductor chip and the passive component. A passivation layer is formed on the LDS activatable molding material.