Package Substrate Adapter for Semiconductor LSI Testing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for manufacturing semiconductor devices with flip-chip configurations face challenges in efficiently converting inter-pad distances for LSI testing, as existing adapter boards are costly and limit design flexibility due to the need for dedicated testing terminals and solder bumps, which restrict the use of package substrates as adapter boards for inter-pad distance conversion.
Innovation Solution
A method involving two package substrates with distinct land pads and testing-dedicated pads, where the second surface has land pads with a larger inter-pad distance and a testing-dedicated pad, allowing for electrical coupling with a probe card and measuring apparatus, enabling LSI testing without external coupling terminals on the testing-dedicated pad, thus preventing unwanted contact and maintaining design flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If adapter board system is employed for converting inter-pad distance, then manufacturing precision for narrow inter-pad distance is improved, but device complexity and cost increase due to dedicated adapter boards
Solution Approach 1:
The package substrate is designed to serve dual functions: as the mounting substrate for the semiconductor element and as the adapter board for LSI testing. By integrating both functions into a single substrate, the patent eliminates the need for separate adapter boards, reducing device complexity while maintaining the capability to convert inter-pad distances for testing purposes
Solution Approach 2:
The patent merges the package substrate and adapter board into a single integrated structure. The substrate includes both land pads for mounting the semiconductor element and testing-dedicated pads for LSI testing, combining what were previously separate components into one unified board that performs both mounting and testing adapter functions
2Adaptability or versatility
If testing-dedicated pads are provided on package substrate, then LSI testing capability is improved, but unwanted contact and malfunctions occur due to external coupling terminals
Solution Approach 1:
The patent extracts the external coupling terminals from the testing-dedicated pads, leaving only the land pads with semiconductor elements mounted. This separation ensures that testing-dedicated pads remain electrically isolated and do not create unwanted contacts with external circuits, thereby preventing malfunctions while maintaining testing capability
Solution Approach 2:
Instead of providing external coupling terminals on testing-dedicated pads as is conventional, the patent inverts the approach by intentionally omitting these terminals. The testing-dedicated pads are left as bare pads without external connections, reversing the conventional design to eliminate the source of unwanted contacts
3Ease of manufacture
If package substrate is used as adapter board, then cost is reduced and design flexibility is improved, but inter-pad distance conversion for testing is limited
Solution Approach 1:
The patent applies local quality by creating different pad configurations in different regions of the substrate. Land pads are arranged with one inter-pad distance for semiconductor element mounting, while testing-dedicated pads are arranged with a different inter-pad distance suitable for LSI testing, allowing the substrate to handle multiple spacing requirements locally
Data Source
AI summary
A semiconductor device, includes a package substrate having a first surface and a second surface opposite to the first surface, and a semiconductor element installed in the first surface of the package substrate. The package substrate includes a plurality of first land pads disposed in the first surface, second land pads disposed in the second surface and a second testing-dedicated pad disposed in the second surface. The semiconductor element is electrically coupled to the first land pads, an inter-pad distance for the second land pads is larger than an inter-pad distance for the first land pads, the first land pad contains a first testing-dedicated pad electrically coupled to the semiconductor element, the first testing-dedicated pad and the second testing-dedicated pad each include a dedicated terminal, which is essential for applying a specified electrical signal from an LSI tester, when an LSI testing is conducted for a semiconductor wafer and the first testing-dedicated pad is electrically coupled to only the second testing-dedicated pad through a wiring.