Semiconductor Package EMI Shielding With Vertical Conductive Pillars
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Solution Overview
Problem
Existing semiconductor package shielding methods are costly, inefficient, and require additional space, with issues such as flux creep, delamination, and extrusion problems in attached shields, and difficulties in encapsulating metal shields within the package.
Innovation Solution
A shielding structure using conductive spaced-apart pillar structures, such as conductive wires formed through wire-bonding, attached to a substrate with distal ends not connected to the substrate, and a conformal shielding layer connected to the pillar structures for enhanced EMI shielding, allowing for reduced package size and cost-effective manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a metal can is attached over the component after attachment to substrate, then EMI shielding is achieved, but manufacturing cost increases and reliability decreases due to flux creep, delamination, and extrusion issues
Solution Approach 1:
The conductive pillars are formed on the substrate before the component is attached, integrating the shielding structure into the packaging process itself rather than adding it as a separate post-assembly step. This preliminary formation eliminates the need for subsequent attachment operations that cause reliability issues.
Solution Approach 2:
The shielding structure is merged with the substrate by directly forming conductive pillars on the substrate surface. This integration combines the substrate and shielding functions into a single unified structure, eliminating the separate attached shield and its associated reliability problems.
2Object-affected harmful factors
If a metal RF shield is directly attached to the semiconductor package substrate, then EMI shielding is achieved, but significant additional space is required on the package substrate
Solution Approach 1:
The shielding structure transitions from a planar two-dimensional shield to a three-dimensional vertical pillar structure. The conductive pillars extend vertically from the substrate surface, providing EMI shielding in the vertical dimension while minimizing the horizontal footprint on the substrate.
Solution Approach 2:
Instead of covering the entire substrate with a continuous shield, conductive pillars are strategically positioned only in specific locations where EMI shielding is most needed. This localized approach provides effective shielding while minimizing the overall space required.
3Object-affected harmful factors
If a metal shield is embedded within the mold compound, then EMI shielding is achieved, but molding process becomes difficult and cost increases
Solution Approach 1:
The conductive pillars are formed on the substrate before mold compound application, allowing the molding process to flow around pre-formed structures rather than attempting to embed rigid metal shields during molding. This sequence eliminates molding difficulties while maintaining shielding effectiveness.
Data Source
AI summary
An electronic device structure having a shielding structure includes a substrate with an electronic component electrically connected to the substrate. The shielding structure includes conductive spaced-apart pillar structures that have proximate ends connected to the substrate and distal ends spaced apart from the substrate, and that are laterally spaced apart from the first electronic component. In one embodiment, the conductive pillar structures are conductive wires attached at one end to the substrate with an opposing end extending away from the substrate so that the conductive wires are provided generally perpendicular to the substrate. A package body encapsulates the electronic component and the conductive spaced-apart pillar structures. In one embodiment, the shielding structure further includes a shielding layer disposed adjacent the package body, which is electrically connected to the conductive spaced-apart pillar structures. In one embodiment, the electrical connection is made through the package. In another embodiment, the electrical connection is made through the substrate.