Semiconductor Package EMI Shielding for Wire Sweep and ESD

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Solution Overview

Problem

Conventional wire bonding packaging techniques face issues with bonding wire sweep during encapsulation, leading to wire deformation and shorting, and there is a need for effective EMI shielding and ESD protection in semiconductor packages.

Innovation Solution

The implementation of insulator-coated bonding wires and a package-level EMI shielding structure, including a component with a metal layer acting as a Faraday cage, to stabilize wires and shield against electromagnetic interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If conventional wire bonding packaging technique is used with increasing number of I/O terminal pads, then the pitch between adjacent bonding wires becomes finer, but bonding wire sweep and deformation occur during encapsulation leading to shorting

Engineering Contradiction:
Improvenumber of I/O terminal padsVSAvoidbonding wire positioning accuracy
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by coating the bonding wires with insulator material before the encapsulation process. This pre-protection measure prevents wire deformation and shorting during molding, allowing finer pitch wiring to maintain its precision throughout manufacturing.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The insulator coating acts as an intermediary layer between the bonding wires and the molding compound. This intermediate protective layer reduces direct mechanical interaction between the molding forces and the wires, preventing sweep and deformation while allowing the fine pitch configuration to be maintained.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If additional process steps or specialized equipment are used to reduce bonding wire sweep, then wire deformation is reduced, but production costs increase

Engineering Contradiction:
Improvebonding wire stabilityVSAvoidproduction cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent merges the insulator coating application with the existing wire bonding process flow, eliminating the need for separate specialized equipment or additional process steps. The insulator material is applied as part of the standard packaging sequence, reducing complexity while maintaining wire stability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The insulator coating provides self-service protection to the bonding wires, enabling them to resist molding forces without requiring external specialized equipment or additional process interventions. This self-protective mechanism reduces manufacturing complexity and cost.

Inventive Principle:
Principle #25Self-service

3Productivity

If plastic molding compound melt flows into mold cavity during encapsulation, then packaging is completed, but forces exerted displace or deform bonding wires causing shorting

Engineering Contradiction:
Improveencapsulation completionVSAvoidbonding wire integrity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The insulator coating serves as beforehand cushioning protection for the bonding wires before the encapsulation process begins. This pre-applied protective layer absorbs and distributes the molding forces, preventing direct transmission of stress to the wires and maintaining their integrity during productivity-critical encapsulation.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The insulator coating functions as a thin film protective shell around the bonding wires. This flexible protective layer allows the wires to maintain their shape and position while withstanding the molding forces, ensuring reliability during the encapsulation process that completes packaging.

Inventive Principle:
Principle #30Flexible shells and thin films

4Shape

If adjacent bond wires come into contact during encapsulation, then wire deformation occurs, but shorting between adjacent wires results

Engineering Contradiction:
Improvebonding wire shapeVSAvoidelectrical isolation between wires
Core Design Contradiction:
ShapeVSReliability

Solution Approach 1:

The insulator coating acts as an intermediary electrical isolation layer between adjacent bonding wires. This intermediate insulating barrier prevents electrical contact and shorting even when wires are in close proximity or experience minor deformations during encapsulation, maintaining reliability while preserving wire shape.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The insulator coating provides localized electrical isolation properties at critical points where wire contact could occur. This local quality enhancement ensures electrical separation is maintained precisely where needed, preventing shorting while allowing the overall wire shape to remain intact.

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 solution prevents wire shorting and enhances EMI shielding, providing mechanical support and protection against ESD, resulting in a more stable and efficient semiconductor package.

Implementation Method 1

insulator-coated bonding wires... to stabilize wires and shield against electromagnetic interference

Methodology Applied
Scientific EffectElectrical insulation: Dielectric

Implementation Method 2

a component with a metal layer acting as a Faraday cage, to stabilize wires and shield against electromagnetic interference

Methodology Applied
Scientific EffectFaraday cage: Faraday Cage

Data Source

PatentEP3772099B1Semiconductor package with EMI shielding structure
Publication Date: 2025.10.22 MEDIATEK INC
  • EP3772099B1 patent drawingFigure 1~2
  • EP3772099B1 patent drawingFigure 3~4
  • EP3772099B1 patent drawingFigure 5~6

AI summary

A semiconductor package includes a carrier substrate (10) having a top surface (10a); a semiconductor die (20) mounted on the top surface (10a); a plurality of first bonding wires (31) connecting the semiconductor die (20) to the carrier substrate (10); an insulating material (41) encapsulating the plurality of first bonding wires (31); a component (200) having a metal layer (204) mounted on the insulating material (41); a plurality of second bonding wires (32) connecting the metal layer (204) of the component (200) to the carrier substrate (10); and a molding compound (50) covering the top surface (10a) of the carrier substrate (10) and encapsulating the semiconductor die (20), the component (200), the plurality of first bonding wires (31), the plurality of second bonding wires (32), and the insulating material (50). The metal layer (204) and the plurality of second bonding wires (32) constitute an electromagnetic interference, EMI, shielding structure.