Stiffened Semiconductor Die Package Warping Prevention
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Solution Overview
Problem
Thin semiconductor die packages often warp during manufacturing, affecting yield and pick-and-place machine performance due to lack of a flat surface, and require increased external connectors for functionality and heat dissipation in small handheld devices.
Innovation Solution
A stiffened semiconductor die package is created by surrounding the die with a conductive frame and encapsulating it in mold compound, attaching a thermally conductive sheet to the inactive side, and using a dielectric support structure with external connector pads selectively coupled to the die bonding pads, along with a method involving temporary support structures and molding processes to enhance rigidity and heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the package thickness is reduced to meet small handheld device specifications, then the device size is reduced, but the package warps during manufacturing affecting yield and pick-and-place machine performance
Solution Approach 1:
The patent employs a composite structure consisting of a semiconductor die, mold compound, and a stiffener layer made of a different material with appropriate mechanical properties. This composite construction allows the package to maintain reduced thickness while the stiffener provides the necessary rigidity to prevent warping during manufacturing and handling, thus resolving the contradiction between thin profile and structural stability.
Solution Approach 2:
The package is segmented into distinct functional layers: the semiconductor die, the mold compound encapsulation, and a separate stiffener component. This segmentation allows each layer to be optimized independently - the thickness can be reduced in the die and mold compound regions while the stiffener is specifically designed to provide mechanical support, thereby achieving both reduced overall thickness and warping prevention.
2Adaptability or versatility
If the number of external connectors is increased to accommodate increased functionality and power supply rail requirements, then the functionality is improved, but the package complexity and size increase
Solution Approach 1:
The stiffener serves multiple functions simultaneously: it provides mechanical support to prevent warping, acts as a thermal management component, and serves as a structural base for mounting external connectors. By making the stiffener multi-functional, the patent accommodates increased functionality requirements without proportionally increasing package complexity, as one component fulfills multiple roles.
Solution Approach 2:
The patent merges the stiffener with the connector support structure, combining what could be separate components into a unified element. The stiffener is designed to integrate with and support the external connectors, thereby reducing the number of separate structural elements needed and managing package complexity even as functionality and connector count increase.
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 provides a rigid and thermally efficient semiconductor die package that reduces warping and facilitates efficient singulation, while also accommodating increased functionality and heat dissipation requirements, ensuring reliable performance in small devices.
Implementation Method 1
a thermally conductive sheet attached to the inactive side of the semiconductor die
Data Source
AI summary
A stiffened semiconductor die package has a semiconductor die including an integrated circuit. The die has an active side with die bonding pads and an opposite inactive side. A conductive frame that acts as a ground plane surrounds all edges of the die and a mold compound covers the conductive frame and the edges of the die. A thermally conductive sheet is attached to the inactive side of the die. A dielectric support structure with external connector pads with solder deposits is attached to the active side of the die. The external connector pads are selectively electrically coupled to the die bonding pads.