What do you do when discontinuation hits?

This article originally appeared in the Jan'24 magazine issue of Electronic Specifier Design – see ES's Magazine Archives for more featured publications.

Written by Marco Mezger, COO of NEUMONDA and President of MEMPHIS Electronic.

Normally, discontinuation is not a big deal. The application system manufacturer upgrades its design to incorporate the product of a different vendor that often has been pre-qualified or moves to a newer technology generation.

3D Plus approached MEMPHIS Electronic in the hope that one of the 18 memory manufacturers in its line card would still have the product. However, the 8Gb DDR3 x32 was a rare product that only a few manufacturers had provided in the first place, and the x32 option had been discontinued by all of them because the volumes sold were just too low. The obvious alternatives of moving to a new DRAM generation or using two individual 4G DDR3 x16 chips in a single package weren’t an option. In this case, a qualified design that has been approved cannot be changed which is common in certain industries like medical or avionic.

When impossible is not in your vocabulary

That’s when the strength of Neumonda came into play, which MEMPHIS Electronic is part of. Part of the group is also the memory IP division called Neumonda Technology which focuses on the development of DRAM components and DRAM test kits. It developed a new prototype of a lightweight DRAM tester that has been designed to conduct vendor-inde[1]pendent tests that also simulate the actual environment in which the DRAM memory is going to be used. With this new approach, it’s not only possible to predict potential failures much more accurately, but also tell how well a DRAM will do in the specific environment. All this at a fraction of the costs of traditional testers.

MEMPHIS introduced 3D Plus to Neumonda Technology and the two companies discussed the exact needs for this project. The team reviewed the requirements with Intelligent Memory, the third company in the Neumonda Group, and the IM team was confident it could manufacture the components that 3D Plus needed. Neumonda Technology then took on the task of testing and qualifying the DRAMs with the prototype of its new Rhinoe Tester, so they would meet the specific requirements of an extended temperature range of -40° to +105°C.

Improved test flow

For the testing process, the DRAMs were placed in the sockets of the test board and then Neumonda’s own test software ran the various tests ranging from burn-in via memory array speed to interface speed tests at wide temperature ranges with the help of a micro-climate chamber. A security guard band was applied to ensure increased retention time and allow for overclocking frequencies. All this testing is conducted without having to unload the DRAMs in a new test platform at the risk of damaging the ball pins.

With this radically new approach, and due to the small size of the tester, the factory flow of testing could be altered. There is no need to move the memory components to the stationary test equipment which often weighs several tons. Contrarily it should be the small and lightweight tester loaded with memory components that moves through the factory. The components simply needed to be loaded onto the tester board once and stayed connected during the entire production flow while all processing steps were executed.

In conventional memory testing, components are loaded and unloaded up to seven times for the different test steps to be executed such as burn-in, array-test and speed test at various temperatures. The process of loading and unloading can potentially damage the package balls and is prone to accidentally mixing up semiconductor components during this traditional test flow.

The tests that the Rhinoe tester runs are based on Neumonda patented IP which does not require any wafer-related IP or insights into the proprietary test modes of the memory manufacturer.

High-quality result The prototype of the tester proved its value: over a period of three years, there were no customer returns. This was thanks to Neumonda Technology being able to simulate the actual application environment in which the product would be used during its testing.

The prototype in the meantime was transformed into today’s Rhinoe tester platform which won an Elektra Award in November 2023. With this unusual approach, MEMPHIS Electronic was able to satisfy the customer by combining the strengths in memory know-how and supply chain with memory manufacturing and an innovative approach to memory testing.