Semiconductor Conductor Layer Anchoring via Reverse Tapered Insulator
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Solution Overview
Problem
The dimensional shrinkage of conductor layers during high-temperature reflow heating in semiconductor devices can cause the conductor layer to peel off from the wiring board, disrupting the electromagnetic shielding structure and rendering the semiconductor device non-functional.
Innovation Solution
A semiconductor device design where the conductor layer is in contact with the surface of a reverse tapered portion of the insulating layer, acting as an anchor to suppress dimensional changes and maintain the connection with the wiring board, ensuring the integrity of the electromagnetic shielding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the conductor layer is provided to enclose the insulating layer with the lower end in contact with the wiring board, then the electromagnetic shielding structure is formed, but the conductor layer dimensionally shrinks during reflow heating and peels off from the wiring board
Solution Approach 1:
The patent applies preliminary action by forming a protrusion on the insulating layer before applying the conductor layer. This protrusion pre-establishes a mechanical interlocking structure that prevents the conductor layer from peeling off during subsequent thermal processing, thereby resolving the dimensional stability issue while maintaining electromagnetic shielding function.
Solution Approach 2:
The patent introduces a third dimension by creating a protrusion that extends vertically from the insulating layer surface. This dimensional change provides an additional anchoring interface for the conductor layer, transforming a two-dimensional contact problem into a three-dimensional mechanical interlock that resists thermal shrinkage forces.
2Reliability
If the conductor layer is made to contact the wiring board for grounding, then the electromagnetic shielding structure functions, but the free end of the conductor layer is pulled and peeled during heat treatment
Solution Approach 1:
The protrusion is formed on the insulating layer before the conductor layer is applied, pre-establishing a mechanical interlocking structure. This preliminary structural preparation ensures that when the conductor layer is later subjected to thermal shrinkage forces during reflow heating, the pre-formed protrusion already provides anchoring resistance, preventing peeling and maintaining the grounding connection.
Solution Approach 2:
The protrusion creates a curved or tapered surface geometry on the insulating layer. This curved surface provides better mechanical interlocking with the conductor layer compared to a flat surface, increasing the contact area and distribution of stress, thereby enhancing the connection strength and resistance to peeling during thermal processing.
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
Prevents the breakage of the connection between the conductor layer and the wiring board due to dimensional changes, maintaining the electromagnetic shielding function and ensuring the semiconductor device operates properly.
Implementation Method 1
conductor paste commonly used as a material for a conductor layer has the property of dimensionally shrinking when subjected to high temperature for a long period of time
Data Source
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AI summary
A semiconductor device functioning properly by maintaining an electromagnetic shielding structure by a conductor layer is provided. A semiconductor device includes a wiring board (1) having a surface, a semiconductor element (5), an insulating layer (8), and a conductor layer (10). The semiconductor element (5) is arranged on the surface of the wiring board (1). The insulating layer (8) is located on the surface of the wiring board (1) and arranged to surround the semiconductor element (5). The conductor layer (10) covers an outer peripheral surface of the insulating layer (8), and is connected to the wiring board (1). The outer peripheral surface of the insulating layer (8) includes an upper surface located over the semiconductor element (5), and a side surface connecting the upper surface and the wiring board (1). The side surface includes a reverse tapered portion (9). The conductor layer (10) is in contact with a surface of the reverse tapered portion (9).