Partially Etched Leadframe for High-Density IC Contacts

Solution Overview

Problem

Current IC packaging technologies face challenges in achieving high-density contacts while maintaining cost-effectiveness, as traditional methods often require complex laminate processes and materials that are not always economically viable.

Innovation Solution

The use of partially etched and selectively plated leadframes, where the leadframe is partially etched on the top surface to create metal traces and plated with bondable materials like silver, gold, or copper, allowing for stable and cost-effective manufacturing of IC packages with high-density contacts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If traditional laminate processes and materials are used to achieve high-density contacts, then contact density can be improved, but manufacturing complexity and cost increase significantly

Engineering Contradiction:

Improvecontact densityVSAvoidmanufacturing complexity

Core Design Contradiction:

Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by modifying the leadframe structure through partial etching and selective plating processes. Instead of using complex laminate materials, the invention changes the physical and chemical parameters of the leadframe itself - creating recesses through etching and applying bondable materials through selective plating - to achieve high-density contacts while maintaining manufacturing simplicity and cost-effectiveness

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention replaces expensive laminate materials with a cost-effective leadframe-based solution. By using standard leadframe materials (copper, nickel, or other metals/alloys) and applying simple etching and plating processes, the patent achieves high-density contacts without the high costs associated with laminate processes, effectively substituting expensive materials with cheaper alternatives

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Quantity of substance

If traditional laminate processes and materials are used to achieve high-density contacts, then contact density can be improved, but manufacturing cost increases significantly

Engineering Contradiction:

Improvecontact densityVSAvoidmanufacturing cost

Core Design Contradiction:

Quantity of substanceVSEase of manufacture

Solution Approach 1:

The patent applies parameter changes by modifying the leadframe structure through partial etching and selective plating processes. Instead of using complex laminate materials, the invention changes the physical and chemical parameters of the leadframe itself - creating recesses through etching and applying bondable materials through selective plating - to achieve high-density contacts while maintaining manufacturing simplicity and cost-effectiveness

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention replaces expensive laminate materials with a cost-effective leadframe-based solution. By using standard leadframe materials (copper, nickel, or other metals/alloys) and applying simple etching and plating processes, the patent achieves high-density contacts without the high costs associated with laminate processes, effectively substituting expensive materials with cheaper alternatives

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Ease of manufacture

If partially etched and selectively plated leadframes are used, then manufacturing cost and complexity are reduced, but achieving high-density contacts becomes more challenging

Engineering Contradiction:

Improvemanufacturing costVSAvoidcontact density

Core Design Contradiction:

Ease of manufactureVSQuantity of substance

Solution Approach 1:

The patent applies local quality by creating recesses in specific locations on the leadframe through partial etching, and by selectively applying bondable materials only to specific areas through selective plating. This localized modification approach allows the leadframe to achieve high-density contacts in critical areas while maintaining cost-effectiveness and manufacturing simplicity overall, rather than requiring complex processes across the entire structure

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention utilizes the vertical dimension by creating recesses in the leadframe surface. This dimensional change allows for increased contact density by utilizing the depth of the recesses to accommodate multiple contact points or larger bonding areas, effectively adding a third dimension to the contact structure without increasing planar complexity

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 enables the production of IC packages with increased stability and higher I/O connections, reducing manufacturing complexity and costs while meeting PCB design specifications for pitch and spacing requirements.

Implementation Method 1

the leadframe is partially etched on the top surface to create metal traces

Methodology Applied

Scientific EffectEtching:

Implementation Method 2

plated with bondable materials like silver, gold, or copper

Methodology Applied

Scientific EffectPlating: Electroplating

Data Source

PatentUS8785253B2Leadframe for IC package and method of manufacture

Publication Date: 2014.07.22 KAIXIN INC

AI summary

A leadframe for use in an integrated circuit (IC) package comprising a metal strip partially etched on a first side. In some embodiments, the leadframe may be selectively plated on the first side and/or on a second side. The leadframe may be configured for an IC chip to be mounted thereon and for a plurality of electrical contacts to be electrically coupled to the leadframe and the IC chip.