Semiconductor Device with Segmented Metal Body for High-Frequency Shielding
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Solution Overview
Problem
Semiconductor devices in high-frequency applications with a large number of elements face challenges in heat dissipation and electromagnetic interference, leading to oscillation and propagation property deterioration when closely packed, especially in 5th-generation mobile communication systems using broad frequency bands and massive MIMO technology.
Innovation Solution
A semiconductor device configuration featuring a first metal body with a die pad portion and a second metal body forming a transmission line, separated and covered by the first metal body, with a molding resin exposing the die bond surface for improved heat dissipation and electromagnetic shielding, inhibiting oscillation and propagation property deterioration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If semiconductor devices are arranged closely to minimize transmission path length, then transmission loss is reduced, but electromagnetic waves from input/output terminals couple with adjacent devices causing oscillation and propagation property deterioration
Solution Approach 1:
The lead frame is segmented into a first metal body (grounded shield) and a second metal body (signal transmission line), with the signal line separated from and covered by the ground shield. This segmentation creates electromagnetic isolation between adjacent semiconductor devices while maintaining short transmission paths, preventing coupling-induced oscillation without increasing transmission loss.
2Area of stationary object
If a heatsink is provided away from the antenna and semiconductor device to accommodate space constraints, then space is saved on the antenna surface, but the heat dissipation path is elongated increasing thermal resistance and reducing output
Solution Approach 1:
The first metal body (ground shield) serves multiple functions simultaneously: it provides electromagnetic shielding for the transmission line, acts as a heat dissipation path for the semiconductor device, and functions as a ground reference. This multi-functionality eliminates the need for separate heatsink structures, maintaining short thermal paths while saving space on the antenna surface.
3Ease of operation
If the second metal body is provided on the same side as the die bond surface, then transmission line configuration is achieved, but space for heat dissipation and electromagnetic shielding is limited
Solution Approach 1:
The transmission line structure transitions from a planar two-dimensional layout to a three-dimensional configuration where the second metal body (signal line) is positioned above the first metal body (ground shield) with vertical separation. This dimensional change allows the signal transmission function to be achieved while the grounded first metal body provides both electromagnetic shielding and heat dissipation in the vertical dimension, resolving the space conflict.
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 configuration enhances heat dissipation efficiency and prevents oscillation and propagation property deterioration in high-frequency applications, even when semiconductor devices are closely arranged, by providing effective electromagnetic shielding and maintaining consistent characteristic impedance.
Implementation Method 1
a first metal body 10 having a die pad portion 11 to which a semiconductor element 1 is mounted... the second metal bodies 20 being separated from the first metal body 10 and covered by the first metal body 10
Implementation Method 2
the molding resin 2 holding the first metal body 10 and the second metal bodies 20 such that a surface of the first metal body 10 opposite to the die bond surface 12 on which the semiconductor element 1 is mounted is exposed
Data Source
AI summary
A semiconductor device according to the present invention includes: a semiconductor element; a first metal body having a die pad to which the semiconductor element is mounted, the semiconductor element being mounted on a die bond surface of the die pad; a second metal body which has a wire bond pad connected to a signal electrode of the semiconductor element via a wire, and is provided on the same side as the die bond surface such that the second metal body is separated from the first metal body and covered by the first metal body, the second metal body forming a transmission line together with the first metal body; and a molding resin holding the first metal body and the second metal body such that a surface of the first metal body opposite to the die bond surface is exposed.