Leadframe Side Terminal Plating Without Sacrificial Wires

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Solution Overview

Problem

Existing methods for manufacturing leadless semiconductor die packages require sacrificial electroplating wires for electrical communication during the electroplating process, increasing complexity and material wastage.

Innovation Solution

A method that maintains electrical communication through tie bars during the formation of side terminals by performing precise cuts using laser cutting, eliminating the need for sacrificial electroplating wires.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If sacrificial electroplating wires are used for electrical communication during electroplating, then electroplating can be performed, but device complexity and material wastage increase

Engineering Contradiction:

Improveelectrical communication during electroplatingVSAvoidmanufacturing process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the sacrificial electroplating wires from the manufacturing process. By maintaining electrical communication through the existing tie bars that connect terminal-forming portions to die-connection portions, the patent removes the need for additional sacrificial wires, thereby reducing device complexity and material wastage while preserving electroplating capability

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The tie bars serve multiple functions: they provide mechanical support, maintain electrical communication during electroplating, and eliminate the need for separate sacrificial wires. This multi-functionality reduces overall device complexity while ensuring reliable electroplating can be performed

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If sacrificial electroplating wires are used, then electroplating can be performed, but material wastage increases

Engineering Contradiction:

Improveelectrical communication during electroplatingVSAvoidmaterial wastage

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

Instead of using and discarding sacrificial electroplating wires, the invention recovers and reuses the existing tie bars for electrical communication during electroplating. The tie bars remain intact and continue to serve their structural and electrical functions, eliminating material wastage associated with sacrificial wires

Inventive Principle:

Principle #34Discarding and recovering

3Ease of manufacture

If precise laser cutting is performed to maintain tie bar integrity, then electroplating can be performed without sacrificial wires, but manufacturing precision requirements increase

Engineering Contradiction:

Improvemanufacturing process simplificationVSAvoidcutting precision

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The invention performs preliminary planning of the cutting paths to ensure tie bar integrity is maintained. By pre-determining that cuts will be made through terminal-forming portions while leaving tie bars intact, the process simplifies manufacturing steps while establishing clear precision requirements for the cutting operation

Inventive Principle:

Principle #10Preliminary action

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

Simplifies the manufacturing process and reduces material wastage by maintaining electrical communication through intact tie bars, allowing electroplating without additional wires.

Implementation Method 1

performing a first cut through the terminal-forming portion and the encapsulation layer so as to form a side terminal

Methodology Applied

Scientific EffectLaser cutting: Laser Ablation

Implementation Method 2

electroplating the side terminal

Methodology Applied

Scientific EffectElectroplating: Electroplating

Implementation Method 3

maintains electrical communication through intact tie bars, allowing electroplating

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP4531078A1Method of and intermediate for manufacturing a semiconductor die package

Publication Date: 2025.04.02 NEXPERIA BV

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AI summary

There is provided a method of manufacturing a semiconductor die package. The method comprises providing a leadframe having a sub-structure and at least one tie bar, the sub-structure comprising a terminal-forming portion in electrical communication with the at least one tie bar. The method comprises bonding a die to the sub-structure. The method comprises encapsulating the sub-structure and the die within an encapsulation layer. The method comprises performing a first cut through the terminal-forming portion and the encapsulation layer so as to form a side terminal, whilst leaving all tie bars substantially intact. The method comprises electroplating the side terminal. The method comprises performing a second cut through the tie bar and the encapsulation layer to singulate a semiconductor die package from the leadframe.