Semiconductor Device Thinning via Columnar Electrode and Molding Resin
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Solution Overview
Problem
Existing semiconductor devices face challenges in reducing the thickness of flip-chip bonded semiconductor chips below 100 μm due to handling difficulties and increased manufacturing costs associated with under fill members.
Innovation Solution
A method involving the formation of a columnar electrode on a semiconductor wafer, flip-chip bonding a second semiconductor chip, and subsequent grinding or polishing to reduce the height, along with the use of a molding portion to expose the electrode and chip surfaces, while eliminating the need for an intermediate substrate and reducing under fill material usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If a semiconductor chip is made thinner to reduce device height, then packaging density is improved, but handling difficulty increases and under fill members become problematic
Solution Approach 1:
The patent replaces the expensive and problematic under fill member with a simple molding resin that serves the same protective function. The molding resin is applied in a liquid state, cured to form a solid protective layer, and then the entire structure is thinned by removing excess material, eliminating the need for separate under fill components.
Solution Approach 2:
The patent changes the physical state of the protective material from a pre-formed solid under fill member to a liquid molding resin that is subsequently cured. This parameter change allows the material to be applied in a fluid state for better conformability, then transformed into a solid protective layer that can be thinned uniformly without compromising structural integrity.
2Reliability
If under fill members are used to protect thin chips during flip-chip bonding, then reliability is improved, but manufacturing cost increases
Solution Approach 1:
The patent merges the functions of the under fill member and the encapsulation resin into a single molding resin system. The liquid resin is applied to cover the chip and bonding area, then cured to provide both the protective under fill function and the final encapsulation, eliminating the need for separate under fill components and reducing manufacturing complexity.
Solution Approach 2:
The molding resin serves multiple functions simultaneously: it acts as the under fill member during bonding, provides encapsulation protection, and enables subsequent thinning operations. This multi-functional material replaces what would traditionally require multiple separate components, reducing both cost and manufacturing steps.
3Length of stationary object
If the second semiconductor chip is thinned to reduce overall device height, then packaging density is improved, but chip strength decreases
Solution Approach 1:
The patent applies the molding resin and cures it before thinning the chip structure. This creates a protective cushioning layer that supports the thin chip during subsequent handling and thinning operations, preventing damage that would otherwise occur when manipulating very thin semiconductor chips.
Solution Approach 2:
The patent creates a composite structure where the thin semiconductor chip is integrated with the cured molding resin. This composite provides the mechanical strength needed for handling thin chips, allowing the chip to be thinned to reduce device height while the surrounding resin matrix provides structural support and prevents breakage.
Data Source
AI summary
A manufacturing method of a semiconductor device includes: forming a columnar electrode on a semiconductor wafer; flip-chip bonding a second semiconductor chip onto the semiconductor wafer; forming a molding portion on the semiconductor wafer, the molding portion covering and molding the columnar electrode and the second semiconductor chip; grinding or polishing the molding portion and the second semiconductor chip so that an upper face of the columnar electrode and an upper face of the semiconductor chip are exposed; and cutting the molding portion and the semiconductor wafer so that a first semiconductor chip, where the second semiconductor chip is flip-chip bonded and the columnar electrode is formed, is formed.