Dual Side Assembly Leadframe with Beveled Cutouts

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Solution Overview

Problem

Conventional packaging methods for microelectronic devices face challenges in providing efficient current conduction, heat dissipation, and noise isolation while being cost-effective and backward compatible with existing manufacturing tools.

Innovation Solution

A package leadframe structure that serves as a low resistance and low inductance interconnect, made primarily of metal alloys, with beveled cutouts to improve current conduction and thermal performance, and allows for dual-side assembly and flexible connectivity between devices, using bondwires or solder bumps for electrical connections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional packaging methods are used, then manufacturing cost is reduced and backward compatibility is maintained, but current conduction efficiency and heat dissipation performance deteriorate

Engineering Contradiction:

Improvecurrent conduction efficiencyVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The leadframe is divided into multiple segments including top leadframe portions, bottom leadframe portions, and interconnect portions. This segmentation allows optimization of each segment for specific functions (current conduction, heat dissipation, mechanical support) while maintaining overall manufacturing efficiency and compatibility with existing processes

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent utilizes three-dimensional leadframe structures with vertical interconnect portions and multi-layer configurations. This dimensional approach enables improved current conduction paths and heat dissipation surfaces without significantly increasing manufacturing complexity, as the 3D structure can be formed using standard leadframe fabrication techniques

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Temperature

If conventional leadframe structures are used, then manufacturing simplicity is maintained, but noise isolation and thermal dissipation performance deteriorate

Engineering Contradiction:

Improvethermal dissipation performanceVSAvoidleadframe structure complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The leadframe structure performs multiple functions simultaneously: top leadframe portions provide current conduction and mechanical support, bottom leadframe portions provide thermal dissipation and structural stability, and interconnect portions provide both electrical connectivity and noise isolation. This multi-functionality reduces the need for separate components, maintaining manufacturing simplicity while improving performance

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The interconnect portions serve as intermediaries between top and bottom leadframe portions, providing controlled impedance paths for signal transmission while isolating noise. These interconnect structures act as mediators that enable improved thermal and electrical performance without requiring complex external shielding or filtering components

Inventive Principle:

Principle #24Intermediary (Mediator)

3Productivity

If dual-side assembly is implemented, then packaging efficiency and connectivity flexibility are improved, but manufacturing process complexity increases

Engineering Contradiction:

Improvepackaging efficiencyVSAvoidassembly process complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The leadframe is segmented into distinct top and bottom portions with dedicated functional areas, allowing independent device placement and assembly optimization on each side. This segmentation enables parallel processing and streamlined manufacturing workflows for dual-side assembly

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the leadframe are optimized for specific functions: top portions for high-current conduction, bottom portions for thermal dissipation, and specific interconnect regions for noise-sensitive signals. This local optimization allows devices to be placed and connected based on their specific requirements, improving packaging efficiency without requiring complex reconfiguration during assembly

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 leadframe structure enhances packaging efficiency by reducing resistance and inductance, improving thermal dissipation, and providing noise isolation, while being cost-effective and compatible with existing manufacturing processes, enabling flexible connectivity and scalable applications in various electronic devices.

Implementation Method 1

The leadframe structure serves as a low resistance and low inductance interconnect

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

improving thermal dissipation

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS8951847B2Package leadframe for dual side assembly

Publication Date: 2015.02.10 INTERSIL AMERICAS INC

AI summary

Embodiments of a leadframe for a device packaging are used not only for structural support and connectivity to the I/O pins to the external world, but also for housing and/or mounting devices above and below the leadframe. Being electrically conductive, the leadframe also serves as a low resistance interconnect and good current carrier between the bondpads on one device or between the bondpads on different devices above and/or below the leadframe.