Leadframe Hole and Ridge for IC Package Pullout Resistance

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Solution Overview

Problem

Current integrated circuit packaging technologies face challenges in achieving high lead density and structural integrity while minimizing package size, which is essential for compact electronic devices, and existing solutions fail to meet these objectives effectively.

Innovation Solution

The method involves forming a package paddle with a lead having a hole and a ridge, mounting an integrated circuit, connecting an electrical connector, and filling the hole with an encapsulation layer to enhance structural integrity and prevent lead pullout.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If conventional leadframe packaging is used to achieve high lead density, then the footprint area is reduced, but the structural integrity and resistance to lead pullout deteriorates

Engineering Contradiction:

Improvefootprint areaVSAvoidstructural integrity

Core Design Contradiction:

Area of stationary objectVSStrength

Solution Approach 1:

The lead is segmented into multiple sections including a body portion, a ridge portion, and a pullout prevention portion with a hole. This segmentation allows each section to perform its specific function while maintaining overall structural integrity and preventing lead pullout in compact packages

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The lead structure extends into the vertical dimension with a hole through the lead body and a ridge portion that protrudes upward. This three-dimensional configuration prevents lead pullout by requiring force to be applied through multiple structural elements rather than a simple planar connection

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Area of stationary object

If lead density is increased to reduce package size, then the footprint area is reduced, but the resistance to lead pullout and misalignment worsens

Engineering Contradiction:

Improvefootprint areaVSAvoidresistance to lead pullout

Core Design Contradiction:

Area of stationary objectVSReliability

Solution Approach 1:

The hole is formed in the lead body and the ridge portion is created during leadframe manufacturing, before the die is mounted and wire bonding is performed. This preliminary structuring ensures that the lead is pre-configured to resist pullout forces and maintain alignment throughout the packaging process and final application

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The wire bond acts as an intermediary element that connects the die to the lead structure. The lead's hole and ridge configuration provides a robust intermediary connection point that prevents both pullout and misalignment of the electrical connection

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS8519518B2Integrated circuit packaging system with lead encapsulation and method of manufacture thereof

Publication Date: 2013.08.27 STATS CHIPPAC LTD

AI summary

A method of manufacture of an integrated circuit packaging system includes: forming a package paddle; forming a lead adjacent the package paddle, the lead having a hole in a lead body top side and a lead ridge protruding from a lead non-horizontal side; mounting an integrated circuit over the package paddle; connecting an electrical connector to the lead and the integrated circuit; and forming a fill layer within the hole.