How to get a RadHard part manufactured - Page 1
Forum section: electronics / projects

author: qwaarjet
author_rank: Regular Contributor
timestamp: April 03, 2015, 07:15:08 pm
content: Is anyone familiar with the process of having a manufacture convert one of their products to a Radiation hardened version. Specifically in my case a high power nMOS that has no equivalent in Hirel/Radhard, that I can find in publicly available datasheets. I'm mainly just trying to inform myself more before calling manufactures.

author: SeanB
author_rank: Super Contributor
timestamp: April 03, 2015, 07:32:29 pm
content: Is it available in an aerospace or space rated variant? If so it is going to pass as radiation hardened, otherwise you are going to be SOL. Most manufacturers only look at making a variant if you can afford to have the maskset made and will pay for the 100 or so wafers they will do as a minimum lot.

author: qwaarjet
author_rank: Regular Contributor
timestamp: April 03, 2015, 08:04:11 pm
content: It is not currently in a aerospace or space rated version. I figured there would be minimum quantity. I most likely will need quantity in the low hundreds for production.

author: SeanB
author_rank: Super Contributor
timestamp: April 03, 2015, 08:12:23 pm
content: I once queried about an obsolete transistor, and the manufacturer still had the process and maskset. They did have a MOQ of 10k parts though, and at around $100 each as well. The one year lead time was a little over the top as well, so I just used a similar equivalent that was off the store shelf. Standard bipolar transistor that, and i really only needed 2, and was looking to get 10 as spares

author: qwaarjet
author_rank: Regular Contributor
timestamp: April 03, 2015, 08:41:06 pm
content: I was guessing the price would 500k-2mil range

author: Balaur
author_rank: Unknown
timestamp: April 03, 2015, 09:07:08 pm
content: What kind of RadHard qualities are important for your application? Military, nuclear industry, automotive, aeronautics or space? TID (Total Ionizing Dose) resiliency only or Single Event resiliency as well?Asking a chip provider to manufacture a radhard version of their products may work if your pockets are deep.My recommendations are the following:Start by investigating existing data (research papers, NASA/ESA reports and so on) about radiation testing of devices close to your requirements. Basically, you are looking for the dose supported by the device (krads) and if your application requires, the Safe Operating Area for the typical maximal Heavy Ions LETs you need to tolerate.EDIT: Also ask the manufacturers for radiation testing reports, even if the devices are not RadHard. They may have something. You may have to ask nicely, reach the appropriate reliability engineer and possibly be a big customer for them.If you find something that respect the requirements, maybe you can fit your system around the device.If not:Gather a short list of device candidates with the requirements you need, including the device you originally used. Buy a few tens of each (<100)Contract a radiation testing company to conduct the TID and HI tests you need, or ask them to recommend the suite of tests that fits whatever specifications you need to follow.It will cost you, though. I would think that less than 100K$ should be OK, potentially half of that if only TID testing is required.It will also take a fair bit of time (3 months is typical).The test reports will hopefully prove that one or several device types fit your requirements. If not, bad luck, you may need to repeat the process with other device references.If you have the relevant test report, you can use the commercial device and prove your final customer that all is good, you did your homework and the device fits the requirements, even if it's commercial.

author: gildasd
author_rank: Frequent Contributor
timestamp: April 03, 2015, 09:12:36 pm
content: I read something about making one off parts Radhard for satellites somewhere, but I can't remember where... It was for diodes or mofsets...But there exists methods out there, not as pretty or light as factory, but workable.Edit: pretty sure it was the Japanese Hayabusa mission.Something about changing parts worth hundred of thousands for other costing a few tens including hardening. But it added weight.

author: Howardlong
author_rank: Super Contributor
timestamp: April 03, 2015, 09:41:18 pm
content: What is the justification for needing a radhard part?There's an awful lot of COTS-only satellites orbiting the Earth.Particularly if your orbit is inside the van Allen belts then there are other, much cheaper ways of mitigating against ionising radiation, usually along the lines of simple redundancy and/or watchdog timers.Parts "qualified" for space are generally only produced in relatively small quantities and so there is a further potential problem of them not being anywhere as nearly well-characterised as COTS equivalents.All of the satellites I've worked on have used COTS parts, and two of those had orbits outside the van Allen belts, but included plenty of mitigation such as targetted aluminium and tantalum shields as well as non-common mode redundancy and self-momitoring.In short, unless you have serious $$$ and are still insisting on radhard, consider designing your application around radhard parts from the start rather than try to bolt it on as an afterthought.

author: qwaarjet
author_rank: Regular Contributor
timestamp: April 03, 2015, 10:21:22 pm
content: This ultimately will be for MEO/GEO.Total dose is than main factor, single event protection is not really an issue since the devices will only be powered sporadically.The reason for custom rad hard part is a trades space problem. Is possible to do it with COTS radhard yes but it requires a fairly large increase in SWaP

author: Howardlong
author_rank: Super Contributor
timestamp: April 03, 2015, 11:29:17 pm
content: Given the orbit details and the date of launch you can get a reasonable estimate of the radiation environment using tools like SPENVIS and CREME96.As Balaur suggested, get some batches of parts and have them characterised with various representative doses found from the modelling to give you an idea if a given device will perform well enough.If you're not interested in single event effects that does simplify the electronic and redundancy design.