Switched Probe Contact for IC Testing Area Reduction
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Solution Overview
Problem
Integrated circuits (ICs) with a small core area face challenges in testing due to the limited space for input/output (IO) cells, requiring increased size or stacking, which complicates probing and testing access.
Innovation Solution
Implementing a switched probe contact that shares a common bond pad between multiple IO cells, allowing selective connection and disconnection using a switch circuit to facilitate testing without the need for additional probe contacts, thereby reducing the overall area required for probing and allowing for a smaller die size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the number of IO cells is increased to improve functionality, then the IC size must be increased or IO cells must be stacked, but this increases the complexity of probing and testing access
Solution Approach 1:
Multiple IO cells share a common probe contact through a switch circuit. The switch circuit allows any of the multiple IO cells to be connected to the single probe contact, enabling testing of multiple cells without requiring multiple separate probe contacts. This merging approach reduces the number of probe contacts needed while maintaining the ability to test all IO cells.
Solution Approach 2:
A single probe contact serves multiple functions by being able to test any of the multiple IO cells through the switch circuit. The probe contact is not dedicated to a single IO cell but can be dynamically assigned to different IO cells based on testing requirements, making it a universal testing interface for all IO cells.
2Adaptability or versatility
If the IC size is increased to accommodate more IO cells, then the desired number of IO cells can be achieved, but the core area becomes less efficient
Solution Approach 1:
Multiple IO cells share a common probe contact, which reduces the space required for probe contacts. This allows more IO cells to be packed into the available area without proportionally increasing the IC size, thereby improving area efficiency while maintaining the desired number of functional IO cells.
Solution Approach 2:
The switch circuit adds a temporal dimension to the probing process, allowing sequential access to multiple IO cells through a single probe contact. This enables more IO cells to be accommodated in the same physical space by utilizing time-multiplexed access rather than requiring simultaneous physical access points for each cell.
3Adaptability or versatility
If probe contacts are stacked to increase IO cell density, then more IO cells can fit on a given length, but the die height increases
Solution Approach 1:
Multiple IO cells share a common probe contact in the vertical dimension, allowing more IO cells to be accommodated without increasing die height. Instead of stacking probe contacts vertically (which would increase height), the invention merges multiple IO cell access through a single probe contact level, maintaining compact vertical profile.
Data Source
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AI summary
Aspects of the present disclosure are directed to methods, apparatuses and systems involving a switched probe contact. According to an example embodiment, an apparatus includes logic circuitry, a first circuit to communicate signals with the logic circuitry, and a first bond pad connected to the first circuit via a first circuit path. The apparatus also includes a second circuit to communicate signals with the logic circuitry, and a second bond pad connected to the second circuit via a second circuit path. A probe contact is connected to the first bond pad and communicates signals with an external probe, and a switch circuit is connected to the probe contact and the second circuit path. The switch circuit communicates signals between the probe contact and the second circuit path by selectively connecting and disconnecting the probe contact to the second circuit path.