Semiconductor Projecting Electrodes via Electrolytic Plating
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Solution Overview
Problem
Conventional semiconductor devices face issues with residual dry film resist left between wiring lines, leading to short circuits and insulation failures during the manufacturing process of chip size packages (CSPs).
Innovation Solution
A semiconductor device and manufacturing method that eliminates the need for dry film resist by forming an overcoat film with openings over wiring lines, where foundation metal layers are deposited within these openings, allowing for the formation of projecting electrodes through electrolytic plating without the steps of forming and releasing a dry film resist.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If dry film resist is used to form columnar electrodes on connection pad portions, then the manufacturing process can proceed with standard photolithography techniques, but residual resist remains between wiring lines causing short circuits and insulation failures
Solution Approach 1:
The patent extracts and removes the problematic dry film resist material from the manufacturing process entirely. Instead of using dry film resist to form columnar electrodes, the invention uses a different approach where the resist is not applied at all, thereby eliminating the source of residual contamination that causes short circuits between wiring lines.
Solution Approach 2:
The patent replaces the reusable dry film resist with a disposable organic-inorganic composite coating that is applied fresh for each electrode formation step and then completely removed. This disposable approach ensures no residual contamination while maintaining the ability to form precise columnar electrodes on connection pad portions.
2Productivity
If dry film resist is applied and then released, then columnar electrodes can be formed, but the resist cannot be completely removed leaving residuals that cause defects
Solution Approach 1:
The patent changes the material parameters of the coating from conventional organic dry film resist to an organic-inorganic composite material. This composite material has different chemical and physical properties that allow it to be completely removed without leaving residuals, while still providing the necessary patterning functionality during electrode formation.
Solution Approach 2:
The patent uses an organic-inorganic composite coating material that combines the advantages of both organic materials (ease of application and patterning) and inorganic materials (complete removability without residuals). This composite approach solves the problem of residual contamination while maintaining manufacturing efficiency.
3Ease of manufacture
If conventional CSP manufacturing process is used with dry film resist, then columnar electrodes with solder balls can be formed, but residual resist causes short circuits and insulation failures
Solution Approach 1:
The patent converts the potential harm of resist material into a benefit by using an organic-inorganic composite that can be completely removed. The coating material serves its purpose during electrode formation and then can be cleanly eliminated, turning what would normally be a contaminant into a temporary, removable protective layer.
Solution Approach 2:
The patent extracts the harmful residual resist component from the manufacturing process by using a composite material that can be completely removed. This extraction eliminates the source of short circuits and insulation failures while preserving the essential function of protecting and defining the electrode structures during manufacturing.
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 prevents residual resist from causing short circuits and defects, ensuring reliable electrical connections and improved manufacturing efficiency by eliminating the need for resist removal processes.
Implementation Method 1
forming, by electrolytic plating, projecting electrodes on the foundation metal layers in the openings of the overcoat film
Data Source
AI summary
A semiconductor device includes a semiconductor substrate, and a plurality of wiring lines provided on one side of the semiconductor substrate, each of the wiring lines having a connection pad portion. An overcoat film is provided on the wiring lines and the one side of the semiconductor substrate. The overcoat film has a plurality of openings in parts corresponding to the connection pad portions of the wiring lines. A plurality of foundation metal layers are respectively provided on inner surfaces of the openings of the overcoat film and electrically connected to the pat portions of the wiring lines. A plurality of projecting electrodes are respectively provided on the foundation metal layers in the openings of the overcoat film.