How Industrial DRAM Withstands Corrosion, Wear & Other Damage

Are DRAM Modules Vulnerable to the Environment?

DRAM modules are vulnerable to humidity, chemicals, dust, and other particles in addition to thermal and mechanical stress, and these vulnerabilities are exacerbated when modules are placed in harsh environments. Due to the increasing rise in the use of DRAM modules and other components in harsh and remote locations brought on by the digitalization trend, industrial manufacturers use conformal coating to safeguard modules, including DRAM.
 

What is Conformal Coating?

Conformal coating is the process of applying a coating agent to components to protect them from the elements. In the case of DRAM, two different coating agents can be used. Acrylic coating agents are easy to apply and remove, making them very convenient when the modules undergo maintenance. Silicone coating agents are able to withstand harsher conditions, but due to being resistant to most solvents and high heat, it is harder to remove them for repair purposes. Both coatings have strong dielectric strengths; therefore they both provide insulation against the outside environment and short-circuit protection.
 

How is Conformal Coating Applied to DRAM Modules?

For Innodisk DRAM modules, the coating is done in full accordance with IPCA-A-610E. The agent is sprayed on at a thickness of between 0.03 to 0.13mm for acrylic agents, and 0.05 to 0.21mm for silicone agents, which is well within the range stated in IPC-J-STD-001. Over numerous sessions, the procedure is repeated with an hour between each session to give the coating time to cure. The curing is carried out using an automated UV light procedure.
   

How is Conformal Coating Removed from DRAM Modules?

If modules require maintenance, the coating must first be taken off. For Innodisk DRAM modules, ultrasound is used for this. The ultrasound causes bubbles to form in tiny crevices between the PCB and the coating. These bubbles therefore make it possible to quickly remove the coating from the module, allowing for additional maintenance to be done.

Do Consumer DRAM Modules Use Conformal Coating?

Generally speaking, consumer DRAM modules, such as those produced for office computers, and gaming systems do not use conformal coating, because these applications do not make good use of the additional protection. However, issues arise when system integrators use consumer DRAM for industrial applications, because without conformal coating, the memory simply cannot survive the harsh environments that industrial modules are often deployed to.

How Does Innodisk Customize Conformal Coating for Each Application?

Since Innodisk performs the entire conformal coating process internally, it is easy to adapt the coating to the demands of the customer. Innodisk can design the ideal coating thickness, coating technique, or coating substance for any application or use case, ensuring longevity.
 

References and Further Reading

1. Innodisk Conformal Coating White Paper
2. Innodisk Conformal Coating Technology Introduction
3. Coatings World 19/02/2014, Innodisk Offers Conformal Coating on DRAM Modules to Protect from Moisture, Dust & Contaminants