Pre-Molded Semiconductor Package Shielding With Exposed Edge Leads
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Solution Overview
Problem
Conventional semiconductor packages face issues of high cost, decreased reliability, and large package sizes, leading to suboptimal performance.
Innovation Solution
The development of semiconductor devices featuring pre-molded substrates with exposed edge leads and inner leads, where a conductive cover contacts the edge lead outward side, providing improved electromagnetic shielding and design flexibility through selective lead connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional semiconductor packages are used, then manufacturing cost is reduced, but reliability decreases and package size becomes too large
Solution Approach 1:
The package structure is segmented into distinct functional zones: a body encapsulant covering the substrate and electronic component, and a separate conductive cover that can be selectively applied. This segmentation allows the package to achieve improved reliability through enhanced electromagnetic shielding while maintaining compact size by only adding shielding where needed, rather than enclosing the entire package.
Solution Approach 2:
The conductive cover is applied locally to specific portions of the package rather than uniformly enclosing the entire structure. This local quality approach provides electromagnetic shielding and reliability improvement in critical areas while avoiding the volume penalty of complete encapsulation, thus resolving the contradiction between reliability and package size.
2Ease of manufacture
If conventional semiconductor packages are used, then manufacturing simplicity is maintained, but cost increases and performance decreases
Solution Approach 1:
The substrate is pre-molded with exposed edge leads and inner leads before the final assembly step. This preliminary action allows subsequent selective connection of leads to the conductive cover, enabling performance enhancement through improved electromagnetic shielding while maintaining manufacturing simplicity by using standard molding and assembly processes in a staged manner.
Solution Approach 2:
The manufacturing process utilizes parameter changes by transitioning from a standard encapsulated structure to one with selective conductive coverage. This parameter change (adding conductive material to specific areas) improves performance through enhanced electromagnetic shielding and signal integrity without fundamentally altering the manufacturing workflow, thus maintaining ease of manufacture while boosting productivity.
3Adaptability or versatility
If conventional semiconductor packages are used, then design flexibility is limited, but cost is lower
Solution Approach 1:
The package design incorporates dynamic adaptability through selective lead connections. Different leads (edge leads and inner leads) can be selectively connected to the conductive cover based on specific application requirements, allowing the same basic package structure to be adapted for different performance needs. This dynamic configuration capability provides design flexibility while relying on standard manufacturing processes to maintain ease of manufacture.
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 results in smaller, more reliable, and cost-effective semiconductor packages with enhanced performance and electromagnetic shielding capabilities.
Implementation Method 1
a conductive cover over the body encapsulant and contacts the outward side of the edge lead. In some examples, the structures and methods can be used in sawn leadless packaging. In some examples, corner portions of the electronic devices can provide additional input/output capability and different leads can be selectively connected with the conductive cover to provide design flexibility. The structures and methods provide for, among other things, improved electromagnetic shielding.
Data Source
AI summary
In one example, a packaged electronic device includes a molded substrate. The molded substrate includes a conductive structure having an edge lead with an edge lead outward side and an edge lead inward side opposite to the edge lead outward side, and an inner lead having an inner lead outward side and an inner lead inward side opposite to the inner lead outward side. The molded substrate includes a substrate encapsulant covering a lower portion of the edge lead inward side, a lower portion of the inner lead inward side, and a lower portion of the inner lead outward side. An upper portion of the edge lead outward side and an upper portion of the inner lead outward side are exposed from the substrate encapsulant. An electronic component is connected to the edge lead and the inner lead. A body encapsulant covers the electronic component and portions of the conductive structure. The body encapsulant has a body encapsulant top side and body encapsulant sides, the upper portion of the edge lead outward side is exposed from one of the body encapsulant sides, and the body encapsulant covers the upper portion of the inner lead outward side and the upper portion of the inner lead inward side. A conductive cover is over the body encapsulant top side, the body encapsulant sides, and outer sides of the substrate encapsulant. The conductive cover contacts the upper portion of the edge lead outward side. Other examples and related methods are also disclosed herein.