Semiconductor Package Fabrication Without Solder Bumping
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Solution Overview
Problem
The existing semiconductor package fabrication processes, particularly those involving flip-mounting of IC devices onto leads, are expensive and complex due to the requirement of solder bumping, which is a costly and intricate process.
Innovation Solution
A method that eliminates the need for solder bumping by forming a passivation body over the IC semiconductor device with openings over each electrode, allowing for flip-mounting onto leads or substrates using a conductive adhesive, such as solder or epoxy, without pre-soldering, thereby simplifying and reducing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solder bumping is performed on the IC semiconductor device before flip-mounting, then the electrical connection and mechanical support are improved, but the manufacturing complexity and cost increase significantly
Solution Approach 1:
The patent extracts the bumping step from the manufacturing process entirely. Instead of forming solder bumps on the IC device, the invention uses the IC device's existing electrodes directly, eliminating the complex bumping process while maintaining electrical connection through conductive adhesive applied at the electrode locations.
Solution Approach 2:
The patent replaces expensive, complex solder bumping with a simpler, cheaper conductive adhesive application process. The conductive adhesive serves as a temporary bonding medium during assembly that provides both electrical connection and mechanical support without requiring the elaborate bumping infrastructure.
2Reliability
If solder bumping is performed on the IC semiconductor device, then the manufacturing cost increases, but the electrical connection quality is improved
Solution Approach 1:
The patent substitutes expensive solder bumping equipment and materials with inexpensive conductive adhesive and a simpler application process. The conductive adhesive provides sufficient electrical connection quality without requiring the high-cost bumping infrastructure, thereby reducing manufacturing costs while maintaining connection reliability.
3Device complexity
If a passivation body is formed over the IC semiconductor device with openings over each electrode, then the need for bumping is eliminated, but an additional fabrication step is added
Solution Approach 1:
The patent merges the passivation layer formation with the electrode exposure pattern creation. The passivation body is formed with integrated openings that simultaneously provide mechanical protection and define the electrode access locations, combining multiple functions into a single fabrication step rather than adding separate steps.
4Ease of manufacture
If flip-mounting is performed without bumping, then the manufacturing cost decreases, but the mechanical support and alignment precision may be compromised
Solution Approach 1:
The patent introduces conductive adhesive as an intermediary material between the IC device electrodes and the substrate. This adhesive layer provides both mechanical support and alignment tolerance, allowing flip-mounting to proceed without precise bumping while maintaining manufacturing precision through the adhesive's bonding characteristics.
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 approach reduces the complexity and expense of fabricating IC packages by eliminating the need for the bumping process, making the method less costly and easier to implement while maintaining electrical and mechanical connections between the IC device and leads.
Implementation Method 1
the adhesive body is adhered to the electrodes of the IC semiconductor device in an appropriate step
Data Source
AI summary
A method for fabricating an IC package that includes depositing conductive adhesive bodies on the leads, and then adhering the electrodes of an IC device to the so disposed conductive adhesive bodies.