Lead Frame-Free Semiconductor Package Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor packages often require lead frames with specific structures, which can limit flexibility and increase development time for new package footprints, as they dictate the position and dimensions of electrical terminals.
Innovation Solution
A semiconductor package design that omits the lead frame, using a metal sheet as a bare lead frame and bonding wires directly to the die, with a mold compound encapsulating the wires and die, and exposing wire ends to form solder bumps, allowing for flexible placement and singulation of packages without the need for a structured lead frame.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a lead frame with specific structure is used, then electrical terminals can be properly positioned and dimensioned, but flexibility and development time for new package footprints are limited
Solution Approach 1:
The patent removes the lead frame structure entirely from the semiconductor package. Instead of using a traditional lead frame to position electrical terminals, the invention directly bonds wires to the die and uses a mold compound to encapsulate and support the structure, thereby eliminating the constraint of lead frame design while maintaining terminal positioning capability
Solution Approach 2:
The invention separates the functions of the lead frame into distinct components: wire bonding for electrical connection, mold compound for structural support and encapsulation, and direct die attachment for positioning. This segmentation allows each component to be optimized independently, enabling flexible package footprint design without being constrained by a unified lead frame structure
2Productivity
If a lead frame is used to support wires and die, then structural stability is provided, but production time increases due to lead frame design requirements
Solution Approach 1:
The patent applies preliminary action by pre-attaching the die to a support structure (such as a carrier or directly to the substrate) before wire bonding. This allows the die position to be established early in the process, eliminating the need for separate lead frame design and assembly steps, thereby reducing overall production time
Solution Approach 2:
The invention merges the support function traditionally provided by the lead frame into the mold compound and substrate structure. The mold compound encapsulates both the die and wires while providing structural support, combining multiple functions into a single material system and eliminating the need for separate lead frame manufacturing and assembly processes
Data Source
AI summary
Implementations of semiconductor packages may include a die including a first side and a second side opposing the first side, the second side of the die coupled to a layer, a first end of a plurality of wires each bonded to the first side of the die, a mold compound encapsulating the die and the plurality of wires, and a second end of the plurality of wires each directly bonded to one of a plurality of bumps, wherein a surface of the layer is exposed through the mold compound.