Non-Volatile Memory Programming Voltage Adjustment for Soldering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Non-volatile memories (NVMs) face challenges in endurance and data retention due to electron fluence during programming and erasing, especially during solder processes, which cause charge loss and reduce the separation between programmed and erased states, affecting reliability.
Innovation Solution
The solution involves programming NVM cells with more energy using a higher reference voltage before soldering to maintain a sufficient separation between states, and then returning to normal operation voltage after a predetermined number of cycles, minimizing the impact on endurance and data retention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If electron fluence is reduced per program cycle to improve endurance, then the number of program/erase cycles increases, but data retention and sensing reliability deteriorate
Solution Approach 1:
The patent applies preliminary action by programming memory cells with a higher reference voltage before soldering to establish a larger initial separation between programmed and erased states. This pre-established separation compensates for the charge loss that occurs during the subsequent soldering process, ensuring that data retention remains reliable even after the soldering operation.
Solution Approach 2:
The patent changes the programming parameter (reference voltage) based on the operational context. A higher reference voltage is used during initial programming before soldering, while normal operation voltage is used afterward. This parameter change allows the system to achieve both improved endurance through reduced electron fluence and maintained data retention through the adjusted programming conditions.
2Reliability
If higher reference voltage is used during programming before soldering to maintain state separation, then data retention after soldering improves, but the programming energy consumption increases
Solution Approach 1:
The higher reference voltage programming is performed as a preliminary action only before soldering, not during all operations. This limited-time application of higher energy ensures sufficient state separation to compensate for soldering-induced charge loss, while avoiding continuous high-energy consumption during normal operation after soldering is complete.
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 ensures reliable data retention and endurance by maintaining a sufficient separation between programmed and erased states, even after soldering, with minimal effect on the number of program/erase cycles.
Implementation Method 1
programming a memory cell of the plurality of non-volatile memory cells by storing charge in a charge storage structure of the memory cell
Data Source
AI summary
A memory system including non-volatile memory cells. The memory system includes program circuitry that programs cells to a first threshold voltage or a second threshold voltage based on the number of times that cells of the memory system have been erased. In one embodiment, the threshold voltage is reduced when any set of cells of the memory system have been erased a specific number of times.