Segmented Wirebond Shielding for IC EMI Suppression
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Solution Overview
Problem
Integrated circuit (IC) modules face challenges in suppressing spurious noise fields due to electromagnetic interference, which existing shielding technologies are unable to effectively address.
Innovation Solution
A segmented shielding method using wirebonds is employed to create a shielded compartment within IC modules, where wires are bonded to a conductive plate, overmolded with an insulating compound, and a shield layer is applied to expose wire ends for enhanced bonding, forming a series of walls to isolate electromagnetic interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If traditional shielding methods are used in IC modules, then electromagnetic interference suppression is attempted, but the shielding effectiveness is insufficient against spurious noise fields
Solution Approach 1:
The patent divides the continuous shield into multiple discrete wire segments arranged in a segmented pattern. Each wire segment acts as an independent shielding element, collectively forming a shield that blocks electromagnetic interference. This segmentation allows the shield to maintain effectiveness while adapting to the compact IC module geometry and avoiding the need for large continuous shield structures.
Solution Approach 2:
The patent transitions from traditional planar or volumetric shielding to a three-dimensional wire-based shield structure. The wires are positioned at specific heights above the substrate and connected to ground planes, creating a vertical dimension for shielding. This dimensional change enables effective EMI suppression in the limited space of IC modules without requiring extensive lateral expansion.
2Device complexity
If wirebonds are used to form shield walls, then shielding structure is created, but manufacturing complexity increases
Solution Approach 1:
The patent uses wirebonds that serve dual functions: electrical interconnection between IC components and structural elements of the electromagnetic shield. The same wires that carry electrical signals also form the shield walls when positioned and grounded appropriately. This multi-functionality eliminates the need for separate shield structures, reducing overall device complexity and manufacturing steps.
Solution Approach 2:
The patent merges the electrical interconnection function and the electromagnetic shielding function into a single integrated structure. The wirebonds that normally only provide electrical connectivity are additionally configured to form shield walls by connecting to ground planes and positioning them strategically. This consolidation reduces the total number of components and simplifies the manufacturing process.
3Strength
If insulating mold is deposited over the module substrate, then component protection is provided, but wire ends become buried and inaccessible for bonding
Solution Approach 1:
The patent performs preliminary positioning and bonding of the wire ends to the ground plane before the insulating mold is fully deposited. The wire ends are strategically placed and connected to ground structures in advance, ensuring their electrical and mechanical integrity is established before encapsulation. This preliminary action ensures that the wires remain accessible and functional even after the mold compound is applied.
Solution Approach 2:
The patent nests the wire ends within cavities or recesses in the insulating mold structure. The mold compound is deposited around the wire ends, creating protective enclosures that maintain wire accessibility. The wires are embedded in the mold structure at specific locations where they remain exposed or accessible for bonding while still being protected by the surrounding insulating material.
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 effectively reduces electromagnetic interference by creating a shielded compartment that isolates noise-generating components, thereby improving the suppression of spurious noise fields within IC modules.
Implementation Method 1
A shield is formed from a series of wires (e.g., wirebonds) to create a wall and/or shielded compartment in an integrated circuit (IC) module
Implementation Method 2
The IC module may be overmolded with an insulating mold compound
Implementation Method 3
Some examples may further laser ablate or otherwise form cavities around the ends of the wires to create stronger bonding between the wires of the shield and the shield layer
Data Source
AI summary
The present disclosure relates to segmented shielding using wirebonds. In an exemplary aspect, a shield is formed from a series of wires (e.g., wirebonds) to create a wall and/or shielded compartment in an integrated circuit (IC) module. The wires can be located in any area within the IC module. The IC module may be overmolded with an insulating mold compound, and a top surface of the insulating mold can be ground or otherwise removed to expose ends of the wires to a shield layer which surrounds the insulating mold. Some examples may further laser ablate or otherwise form cavities around the ends of the wires to create stronger bonding between the wires of the shield and the shield layer.