Integrated Shield for No-Lead Semiconductor Package
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Solution Overview
Problem
Existing semiconductor devices face challenges in reducing electromagnetic interference (EMI) due to their small size and high operating frequencies, which require complex and costly separate metal enclosures for shielding, wasting space and increasing fabrication complexity.
Innovation Solution
An integrated electromagnetic shield is incorporated into a flat, no-lead semiconductor device package using a conformal coating over the overmold body and exposed contact pads, which encompasses both inner and outer rows of contact pads, providing effective EMI protection without the need for a separate metal enclosure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a separate metal enclosure (can) is used to shield the semiconductor device package, then electromagnetic interference (EMI) protection is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent merges the shielding function with the existing package structure by integrating a conductive layer into the mold compound or lead frame. This eliminates the need for a separate metal enclosure, reducing fabrication complexity while maintaining EMI protection. The conductive layer is formed as part of the packaging process, combining multiple functions into a single integrated structure.
Solution Approach 2:
The patent extracts the shielding function from the traditional separate metal can and incorporates it directly into the package components. By taking out the need for a discrete enclosure and integrating conductivity into existing structural elements, the design simplifies manufacturing while preserving EMI shielding effectiveness.
2Object-affected harmful factors
If a separate metal enclosure (can) is used to shield the semiconductor device package, then electromagnetic interference (EMI) protection is improved, but manufacturing cost increases
Solution Approach 1:
The shielding function is merged with the mold compound or lead frame structure, eliminating the need for separate metal can fabrication, assembly, and grounding operations. This integration reduces manufacturing steps and associated costs while maintaining EMI protection effectiveness.
Solution Approach 2:
The patent uses cost-effective materials such as conductive epoxy, metalized mold compound, or lead frame extensions instead of expensive separate metal enclosures. These integrated conductive structures provide adequate shielding at lower material and processing costs.
3Object-affected harmful factors
If a separate metal enclosure (can) is used to shield the semiconductor device package, then electromagnetic interference (EMI) protection is improved, but space around the semiconductor device package is wasted
Solution Approach 1:
The shielding function is merged into the package footprint itself, with the conductive layer formed within or as part of the package structure. This eliminates the need for additional external space that would be required for a separate metal can, maximizing space utilization while providing EMI protection.
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 integrated shield effectively reduces EMI by grounding the outer row of contact pads, thereby minimizing electromagnetic interference while maintaining a compact design and reducing manufacturing costs.
Implementation Method 1
A conformal coating is applied substantially over the upper surfaces of the overmold body as well as the exposed upper surfaces of the contact pads of the outer row of contact pads to provide an integrated shield
Data Source
AI summary
The present invention integrates a shield on a flat, no-lead (FN) semiconductor package, which has multiple rows of contact pads along any side. The FN semiconductor package will have at least one inner row and one outer row of contact pads on at least one side. The inner and outer rows of contact pads and a die attach pad form the foundation for the FN semiconductor package. A die is mounted on the die attach pad and connected by wirebonds to certain contact pads of the inner rows of contact pads. An overmold body is formed over the die, die attach pad, wirebonds, and inner row of contact pads, and substantially encompasses each contact pad of the outer row of contact pads. A conformal coating is applied over the overmold body, including the exposed surfaces of the contact pads of the outer row of contact pads, providing a shield.