Semiconductor Device Adhesive Fillet Thickness Reduction
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Solution Overview
Problem
Conventional semiconductor devices face challenges in reducing the overall thickness due to the requirement of an underfill resin between the solder resist layer of the wiring substrate and the semiconductor chip, which increases the device thickness.
Innovation Solution
A semiconductor device design that includes a wiring substrate, a semiconductor chip, conductive paste, and an adhesive layer, where the adhesive layer covers the entire surface of the insulating layer, connects the wiring layer and the semiconductor chip's electrode pad, and extends to form a fillet on the chip's side surface, eliminating the need for an underfill resin and reducing the device thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an underfill resin is used between the solder resist layer and the semiconductor chip, then the bonding reliability is improved, but the device thickness increases
Solution Approach 1:
The patent merges the functions of the underfill resin and the adhesive layer into a single integrated adhesive layer. This adhesive layer simultaneously provides bonding between the wiring substrate and semiconductor chip, fills the gap between them, and extends to form a fillet on the side surface, thereby eliminating the need for a separate underfill resin layer and reducing overall device thickness while maintaining bonding reliability
Solution Approach 2:
The adhesive layer is designed to perform multiple functions: it bonds the wiring substrate to the semiconductor chip, fills the gap between them, and extends to form a protective fillet on the side surface. This multi-functional design replaces the traditional underfill resin structure, achieving both reliable bonding and reduced device thickness
2Reliability
If the adhesive layer covers the entire surface of the insulating layer, then the bonding area is increased, but the manufacturing complexity increases
Solution Approach 1:
The adhesive layer is applied in advance to cover the entire surface of the insulating layer before the semiconductor chip is mounted. This preliminary application ensures complete coverage and maximizes bonding area, while the excess adhesive automatically forms the fillet structure, simplifying the overall manufacturing process by eliminating the need for separate fillet formation steps
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
This design effectively reduces the thickness of the semiconductor device by approximately 30 μm compared to conventional devices and enhances moisture resistance by forming a fillet on the semiconductor chip's side surface.
Implementation Method 1
The adhesive layer fills in a gap between the surface of the insulating layer and the circuit-formation surface, to bond the wiring substrate and the semiconductor chip
Data Source
AI summary
A semiconductor device includes a wiring substrate, a semiconductor chip, conductive paste, and an adhesive layer. The wiring substrate includes an insulating layer and a wiring layer on a surface of the insulating layer. The semiconductor chip includes a circuit-formation surface in which an electrode pad is provided, and is mounted on the wiring substrate with the circuit-formation surface facing toward the wiring layer. The conductive paste electrically connects the wiring layer and the electrode pad. The adhesive layer is over the entirety of the surface of the insulating layer, and covers the wiring layer and the conductive paste. The adhesive layer fills in a gap between the surface of the insulating layer and the circuit-formation surface, to bond the wiring substrate and the semiconductor chip. The adhesive layer extends onto a side surface of the semiconductor chip to form a fillet.