Semiconductor Frame With Arms For Thermal Dissipation
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Solution Overview
Problem
Existing IC packaging methods face issues such as thermal expansion mismatch defects, warping of carrier strips, and inadequate thermal dissipation, as well as insufficient fan-out density of input-output contacts.
Innovation Solution
A semiconductor device design featuring a metallic frame with a rectangle-shaped IC die pad and diagonally extending arms coupled to a circuit board, along with bond wires and encapsulation material, which provides enhanced thermal dissipation and mechanical protection, and a method for manufacturing this device that includes forming a circuit board with an opening, positioning the frame, and forming bond wires and encapsulation material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional IC packaging methods are used, then manufacturing simplicity is maintained, but thermal expansion mismatch defects and warping occur
Solution Approach 1:
The packaging structure is segmented into multiple functional components: a frame with arms extending from an IC die pad, each arm having a first portion coupled to the die pad and a second portion coupled to the circuit board. This segmentation allows different portions to handle different functions - the IC die pad provides thermal expansion compensation, while the arms provide mechanical support and electrical connection, thereby preventing defects without requiring overly complex packaging
Solution Approach 2:
The frame is constructed from materials with specific thermal expansion properties that match or compensate for the IC and circuit board materials. By using composite material design where the frame material is selected based on CTE matching requirements, thermal expansion mismatch defects are prevented while maintaining a relatively simple packaging structure
2Stability of the object's composition
If carrier strip packaging is used, then ease of manufacture is maintained, but warping and wafer bow occur
Solution Approach 1:
The frame structure is divided into the IC die pad and multiple arms, where the arms are positioned at specific locations to provide targeted mechanical support. This segmentation allows the arms to act as stiffening elements that prevent warping and maintain flatness without requiring a completely different manufacturing process from traditional carrier strip methods
Solution Approach 2:
The frame's physical parameters such as arm thickness, length, and material properties are optimized to provide sufficient mechanical support against warping. By adjusting these parameters, the frame achieves the required flatness and stability while remaining compatible with existing manufacturing processes
3Temperature
If QFN package is used, then size and weight are reduced, but thermal dissipation capability is insufficient
Solution Approach 1:
The frame extends in the vertical dimension with arms reaching from the IC die pad down to the circuit board, creating a three-dimensional thermal conduction path. This dimensional extension allows heat to be conducted from the IC through the frame arms to the circuit board without significantly increasing the horizontal footprint, thus improving thermal dissipation while maintaining compact package size
4Strength
If additional stiffeners are added, then mechanical support is improved, but device complexity increases
Solution Approach 1:
The frame arms serve multiple functions simultaneously: they provide mechanical support and stiffness to prevent warping, establish electrical connections between the IC and circuit board, and facilitate thermal dissipation. By making the frame multi-functional, additional dedicated stiffeners are not required, maintaining package stiffness without increasing device complexity
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 solution effectively addresses thermal expansion mismatch and warping issues while offering improved thermal dissipation and increased fan-out density of contacts, maintaining package stiffness without additional stiffeners and enhancing mechanical protection.
Implementation Method 1
the semiconductor device may effectively radiate thermal energy
Data Source
AI summary
A semiconductor device includes a substrate that includes an opening extending through a thickness of the substrate, a frame that includes an integrated circuit (IC) die pad in the opening and a plurality of arms extending outwardly from the IC die pad, an IC mounted on the IC die pad, a plurality of bonding elements electrically coupling the substrate with the IC without the frame being an intermediary coupling element, and an encapsulant surrounding the IC, the plurality of bonding elements, and the plurality of arms. The substrate has a first major surface and a second major surface. Each arm is devoid of a contact pad. Each arm has a distal end coupled to the first major surface of the substrate, and each arm has a proximal end disposed over the first major surface of the substrate.