IC shelf Life, how long is to long - Page 1
Forum section: electronics / general

author: gogoman
author_rank: Regular Contributor
timestamp: May 03, 2023, 02:56:30 am
content: Hello, If the IC isnewand stored properly (ESD bag 25-40C & 30-40RH), In general what is the shelf life, how old is to old, 5, 10, 20 years?Will a new 20year old device last as long as a recent version?Does the shelf life depend on the IC Type (logic gate, Transistor, cmos/nor flash, programmable logic)?Does the silicon structure deteriorate while on the shelf?thanks

author: retiredfeline
author_rank: Frequent Contributor
timestamp: May 03, 2023, 03:27:31 am
content: Most ICs die of technical obsolescence rather than aging processes like corrosion.I have ICs from 50-60 years ago that still run.

author: gogoman
author_rank: Regular Contributor
timestamp: May 03, 2023, 04:15:11 am
content: If the old never used device were to fail, I suspect the materials are decomposing. It's not clear to me which parameters (timing, threshold etc. ) are effected and in what order.What type of devices are you using?

author: Halcyon
author_rank: Unknown
timestamp: May 03, 2023, 04:26:42 am
content: The only issues I've have storing IC's (mostly DIP packages) is that some of the tubes use rubber (or rubber-like) stoppers. After many years, the stopper material can go hard and leach some oily liquid all over everything. I found this with a bunch of old 3COM boot ROMs.I use IC tubes with holes and those hard plastic pins instead.

author: retiredfeline
author_rank: Frequent Contributor
timestamp: May 03, 2023, 05:43:28 am
content: Quote from: gogoman on May 03, 2023, 04:15:11 amI made a binary clock with DTL chips.https://hackaday.io/project/168075-dtl-binary-clock

author: Jeroen3
author_rank: Super Contributor
timestamp: May 03, 2023, 05:51:26 am
content: It is mostly the deterioration of the metals that make the part solderable.

author: james_s
author_rank: Super Contributor
timestamp: May 03, 2023, 06:13:20 am
content: There is no defined shelf life with most ICs and other semiconductors, it's not uncommon to find 50+ year old parts that still work just fine. There are some specific parts that do deteriorate due to manufacturing defects but it's not common.

author: Berni
author_rank: Super Contributor
timestamp: May 03, 2023, 06:31:33 am
content: As people said chips last pretty much forever.They are encased in solid packages, the bonding wires are gold so they don't corrode, the chip surface tends to be pasivated, so it is essentially encases the chip under a microscopic layer of glass.However there are some old chips out there where the chip fab didn't quite have the process turned quite right, or had contamination issues etc.. so some of these chips can start to die off after a few decades, they are still not guaranteed to die after X years, just that a fairly high percentage of chips ends up randomly giving up the ghost in that time period. For example some of the MOS Technology chips in the Commodores do that.

author: jonpaul
author_rank: Super Contributor
timestamp: May 03, 2023, 06:35:08 am
content: We have boxes of old ICs, analog linear, digital, ADC, DAC from 1970s...1990s, all are fine.Chinese knockoffs, pulls, and illegal clones, perhaps notJ

author: Kleinstein
author_rank: Super Contributor
timestamp: May 03, 2023, 08:32:47 am
content: The can be an issue with surface corrosion, that makes them a little harder so solder (need more agressive flux). This is especially the case of parts of the packaging gives of gases.For SMD parts humidity can be an issue an may want a bake out to prevent popcorn in reflow process.There were a few old semiconductor parts that do go bad over time: Selenium diodes, Germanium transistor (the chip and tin wiskers) and some early silicon chips with the purple plague (e.g. MOStek chips). When stored relatively cool this would be less of an issue, but at 30 C and could be.

author: Gyro
author_rank: Super Contributor
timestamp: May 03, 2023, 09:43:55 am
content: The low RH storage should have avoided most problems, eg. solderability. 20 years isn't long in semiconductor life terms.

author: Benta
author_rank: Super Contributor
timestamp: May 03, 2023, 10:40:24 am
content: There's an issue with SMD parts due to the soldering method. Even at low RH, the epoxy will still absorb water.This leads to phenomenon called "popcorning", where steam pockets in the epoxy are formed when heating up the IC and resulting in cracks.This normally doesn't happen on DIP parts, as only the leads are heated.

author: wraper
author_rank: Unknown
timestamp: May 03, 2023, 10:46:28 am
content: The major problem is with solderability. Unless terminals are gold plated it can deteriorate quite a bit. As of moisture, if components are moisture sensitive, you can bake them which is a normal manufacturing process actually, and is mandatory for some very moisture sensitive components regardless of storage conditions.

author: andy2000
author_rank: Frequent Contributor
timestamp: May 03, 2023, 01:41:31 pm
content: I've seen a lot of ICs that were stored in ESD safe foam rubber. This should be avoided because the rubber often degrades, and corrodes the pins. It can get so bad that even gold plated pins corrode and fall off.

author: RoGeorge
author_rank: Super Contributor
timestamp: May 03, 2023, 02:05:49 pm
content: The old ones I have, either NOS or reused (things like opamps, TTLs and microprocessors from 30-40 years ago) are still working fine every time I happen to use one. No particular care was taken to store them.In some rare situations the pins might need a clean, when they were covered by black oxides. Use a pencil eraser to rub out the oxides, it cleans very well. Then brush the chip with a paintbrush or similar, to remove any pencil eraser debris.For the SMD parts it's a different story, because they are usually soldered by flooding the entire capsule with heat. The material used for encapsulate the chips can absorb humidity, and when heated they might pop like popcorn.For long term stored SMD chips it is recommended to slowly bake them (dry), before oven soldering.

author: BillyO
author_rank: Super Contributor
timestamp: May 03, 2023, 02:31:25 pm
content: Keep them dry and they should last centuries.

author: jonpaul
author_rank: Super Contributor
timestamp: May 05, 2023, 07:24:40 am
content: All:100% re old DIP on foam rubber, corrosion due to outgassing.Certain SMD gull wing parts have cheap plating on the pins. Thus after years of storage, the pins have poor solderability and can result in cold solder joints.Jon

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: May 05, 2023, 02:08:06 pm
content: I have 50+ year old ICs that work fine. Various MECL and RTL parts from the '60s, some still in a little plastic carrier.OTOH there are certain old ICs known for particular failure modes just sitting there. The PLA inside the C64 for example, Commodore made their own and the story is there was too much boron in some layer that eventually causes failure no matter how well it is stored.

author: gogoman
author_rank: Regular Contributor
timestamp: May 05, 2023, 02:10:48 pm
content: Appreciate the inputgogo