Wafer Probe Pad Contact Sequencing for Reliable NAND Testing
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Solution Overview
Problem
Communication reliability between a probe electrode and a pad electrode is suppressed from being degraded.
Innovation Solution
A storage system comprising a storage wafer with a plurality of NAND flash memories and a prober that includes a probe card with NAND controller chips, which electrically couples the storage wafer and the probe card by physically contacting them, and includes a control unit to manage temperature and displacement for precise alignment and communication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the prober repeatedly contacts the storage wafer for testing, then productivity increases, but communication reliability between probe electrode and pad electrode degrades
Solution Approach 1:
The patent controls temperature parameters during the probing process to prevent degradation of the pad electrode contact surface. By maintaining temperature within a specific range, the communication reliability is preserved even after repeated touchdown operations, thus resolving the contradiction between productivity and reliability.
2Reliability
If temperature control is implemented to maintain communication reliability, then reliability improves, but device complexity increases
Solution Approach 1:
The patent introduces a temperature management mechanism as an intermediary between the prober and storage wafer. This intermediary component controls the thermal environment during probing, ensuring communication reliability without requiring fundamental changes to the probing system architecture, thus limiting the increase in device complexity.
3Reliability
If precise alignment is maintained through displacement control, then communication reliability improves, but manufacturing precision requirements increase
Solution Approach 1:
The patent implements displacement control with feedback mechanisms that monitor and adjust the alignment between probe electrodes and pad electrodes during the probing process. This feedback system maintains communication reliability by compensating for alignment variations without requiring extremely tight manufacturing tolerances, thus reducing the burden on manufacturing precision.
Data Source
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AI summary
The present invention curbs degradation in communication reliability between a probe electrode and a pad electrode. A storage system of one embodiment is provided with: a wafer comprising a memory chip unit that includes a pad electrode having a first portion and a second portion that are electrically connected to one another, and comprising a memory cell array electrically connected to the pad electrode; and a prober that is capable of holding the wafer and that reads/writes to/from the memory cell array. The prober comprises: a probe card having a probe electrode allowing for contact with the pad electrode, and having a memory controller capable of writing/reading to/from the memory cell array via the probe electrode; and a movement mechanism for causing the probe card or the held wafer to move, in order to bring the pad electrode of the held wafer and the probe electrode into contact. The movement mechanism is capable of executing: a first operation for bringing the probe electrode into contact with the first portion of the pad electrode without coming into contact with the second portion; and a second operation for bringing the probe electrode into contact with the second portion of the pad electrode without coming into contact with the first portion