Semiconductor Pad Multiplexing for μ-Bump Test Access
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The increasing complexity and integration of semiconductor devices pose challenges in testing due to the small size of μ-bump pads, making direct probing difficult and requiring additional test chips for reliable testing, which complicates the process and increases costs.
Innovation Solution
A semiconductor device design that includes a plurality of bump pads with a test data selector and fewer test pads, allowing for reliable testing without additional test chips by using pad multiplexers and buffers to select and synchronize data between bump pads and test pads, and a delay adjuster to synchronize test data, enabling efficient data exchange and measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the μ-bump technique is applied to increase I/O pins, then the capacity and integration of semiconductor devices are improved, but the bump pad size becomes very small making direct probing difficult
Solution Approach 1:
The patent introduces an intermediary structure consisting of a test data selector and test pads. The test data selector multiplexes data from multiple bump pads to a smaller number of test pads, which are larger and easier to probe. This intermediary layer allows access to the small bump pads through larger test pads, resolving the contradiction between high I/O capacity and probing difficulty.
2Productivity
If the bump pad size is reduced for μ-bump mounting, then the integration density is improved, but the reliability of direct testing is worsened
Solution Approach 1:
The test data selector acts as an intermediary that collects data from multiple small bump pads and presents it through larger test pads. This ensures reliable testing by using the larger test pads for signal acquisition while maintaining the high integration density enabled by small bump pads.
Solution Approach 2:
The patent segments the testing function by separating the bump pads (for data exchange) from the test pads (for testing). The test data selector divides the data from multiple bump pads into manageable groups that can be accessed through fewer, larger test pads, ensuring reliable testing without compromising integration density.
3Reliability
If additional test chips are used to enable reliable testing, then the test reliability is improved, but the device complexity and cost increase
Solution Approach 1:
The test data selector and test pads structure enables the bump pads to serve dual purposes: data exchange during normal operation and testing during wafer test. This multi-functionality eliminates the need for separate test chips, reducing device complexity while maintaining test reliability.
Solution Approach 2:
The semiconductor device performs self-testing through the integrated test data selector and test pads. The device can test itself during the wafer test process without requiring external test chips, making the testing process simpler and more cost-effective while maintaining reliable testing.
Data Source
AI summary
A semiconductor device is provided. The semiconductor device applies data applied through a bump pad on which a bump is mounted through a test pad to a test apparatus such that the reliability of the test can be improved. The amount of test pads is significantly reduced by allowing data output through bump pads to be selectively applied to a test pad. Data and signals applied from test pads are synchronized with each other and applied to bump pads during a test operation such that the reliability of the test can be improved without the need of an additional test chip.